Knockback and leak advice needed

[wmhjr]

Guys, I've read a number of threads concerning knockback but I think I need a little more clarity if possible.

Here's the setup. Moser 12 bolt rear end, "new style Ford Torino" axle flanges and sealed ball bearings. 33 spline axles, Truetrack, Wilwood 12.2" 4 piston Dynalites in the rear. I have two different but possibly related issues.

I'm getting knockback - seriously - especially on autox. At Heidts this past weekend, on that last hard right (almost 180deg) turn, I have about zero brakes going into the turn unless I pump twice. If I don't put side loading on the car, brakes are perfect. BTW, I'm running 14" Superlite 6Rs up front. I also have some gear lube leaking out the axle flanges.

Here's what I've done. I've replaced the axle seals - several times, including in the parking lot of the host hotel at Heidts. I've replaced the "old" type Wilwood bearing retainer bracket with the "new" one that puts more peload (frankly, there was zero before) on the bearing.

I've talked to both Moser and Wilwood. Moser seems to think a tapered bearing might do better but cannot promise it will eliminate the knockback. They think the outer seal on the tapered bearing "might" do better in the leak area, and are pointing to a failed ball bearing as the cuplrit for the leaks? As if the inner seal has no purpose? They claim that Strange and others don't even use an inner seal. I'm a little skeptical. Moving to a tapered bearing means replacing my axles, which isn't cheap though if that is what it takes to fix it, I'll do it. Just don't want to spend the money on axles and tapered bearings only to end up with the exact same issues.

I'm thinking maybe size a shim for inside the housing for the bearing (either tapered or ball bearing) to get the bearing more outboard and allow significant more preload? And maybe add some reinforcement on the bearing retainer so it can't flex? Honestly, the parking brake is useless for me so I could even just totally eliminate it. Not sure.

I frankly don't understand why Moser would pretty much ignore the inner seal leaking.

Anyway, I'd love to hear some more ideas or thoughts about where my head is at.

[Bow Tie 67]

Bill,

I'm running the tapered bearings on my Moser 9", ( Timken set20 ) I consider them a must for the side loading you experience on the track. They will not cure your knock back but should help it out. They have no inner seal and with the movement from side-loading will cause the outer seal to leak at some point. I now consider the rear axle bearings to be a wear item with the type of abuse they are exposed to. My driver side has been replaced twice in 9k miles, unfortunately the bearing gets damaged when removed to replace the seal so it ends up getting a new bearing assy.

Here is a link to what the set20 bearing assy and locking collar look like.

https://catalog.foothilloffroad.com/product_info.php?cPath=74_105&products_id=512&osCsid=nrlzpdwpknp

P.S. Sorry I bolted without saying goodby but I had to get home early.

[silver69camaro]

Definetly a tapered bearing! It should help quite a bit along with a thick (1/4") retainer plate. Depending on your amount of grip it should eliminate most of the knockback (to where the brakes are still functional, just more pedal travel).

The seal on the Set 20 bearings works pretty well. I've never had one leak.

By the way, what is your wheel width and backspace? This plays a big role in knockback.

[wmhjr]

Matt, no worries about leaving. My dad said you stopped by when you were leaving, but I was out thrashing the pontiac on the speed stop. I think you left most of a case of power-aid, which my son has already confiscated! BTW, nice job on the overall event. Once again you and the car are impressive out on the track. Had we not both been in group B, I would have tried to get you in my car and vice versa.

Thanks for the info about the set20 bearing assembly. When you say it did not cure your knock back but helped, I'm curious how much of an improvement you thought it was.

I'm also curious how this would install. when I talked to Moser, they said I'd need to change to different axles to go with the tapered bearing. There would be press ring that goes inside the housing first, then the race, then the bearing/seal which is pressed on the axle, right? And the preload is still accomplished by the same bearing retainer provided by wilwood?

[wmhjr]

Definetly a tapered bearing! It should help quite a bit along with a thick (1/4") retainer plate. Depending on your amount of grip it should eliminate most of the knockback (to where the brakes are still functional, just more pedal travel).

The seal on the Set 20 bearings works pretty well. I've never had one leak.

By the way, what is your wheel width and backspace? This plays a big role in knockback.

Matt, thanks. My wheels are 18x10", 6.125" BS. I actually thought that the wheel geometry was pretty mild and should not hurt as far as knockback. It actually doesn't really matter much, as I don't have flexibility to adjust that (unfortunately).

Oh, Also I'm thinking about making a set of 1/4" retainers myself. I may use the Wilwood retainer with the lip pointing toward the center, then put the 1/4" or 3/8" thick ones outside of that? Thoughts? I just don't know if I need that "lip" if I go to a tapered bearing. Does the bearing surface protrude from the housingi or is the lip still required for preload? Or should I just think about adding a thin machined shim inside the housing to place the outside of the axle where I want it?

[wmhjr]

BTW, do only "Matts" answer this thread? :)

[parsonsj]

Those ball bearings have got to go. You need to get to a tapered bearing (the Set20); it's got to be the biggest contribution to knockback on your setup.

Having said that, chances are you'll still have some, but you may find it livable. If you do decide to tackle an axle swap, ask Moser about their Hobby Stock axles. They will give you the best chance of the most reduction in knockback.

[Bow Tie 67]

Bill I'm running floating calipers so I dont have knock-back issues. Todd Akes ? Vegas69 on Lat-g has dealt with Knock-back extensively, do a search over there. The housing end is different for the Set20 setup, I'll try and find picks of mine. The installation of the set20 on the axle is seal then bearing the press on retainer collar. Removal is split collar and then press axle out of bearing, which is why the seal is destroyed.

Matt Jones I'm curious what is the rear end setup on your car? Do you seal the outer section of the set20 with rtv? I cant believe you have no seepage and track the car.

[silver69camaro]

A 10" rim with 6.125" B.S. is pretty good for minimizing leverage on the bearing. With that in mind, I'm with J.P. that the ball bearing is probably your biggest contributor.

For the retainer, you need to have that lip in place to compress the seal correctly. Currie has a 1/4" replacement for Wilwood brakes, although it's a full-circle retainer and you'd have to pull your bearings off (which I guess you're doing that anyway). That might be your best bet. I made mine as a full circle design, but it's a interlocking 2-piece so I can remove it when I need to.

See here for the retainer plate:
http://www.currieenterprises.com/cestore/productsRE.aspx?id=3267

Matt, my axle is a Ford 9" made here with Torino style ends. I've never had any seepage with mine, and I know Art hasn't had any either on both of his rigs. We make our own housing ends (forgings and all), so that might have something to do with it. Nothing wrong with smearing some RTV in there, though.

[Bow Tie 67]

My retainers dont compress the lip, they actually have a step in them. Matt do you have the dimension from bearing seat to outer housing end where the retainer mounts? I was always worried about flipping the retainer and putting to much pre-load on the bearing. When the bearing is new and the outer seal has not seen the track I have .015 to .020 end play. After track time is will slowly increase depending how many track days I complete.

[wmhjr]

Matt, I've thought about floaters in the back, but am not aware of a relatively cost effective and non-destructive option. I'm concerned that I'm very happy with braking except for the knockback and don't want to trade one problem for another. I don't believe Wilwood has a solution for me, but I'm going to talk to those guys again.

I'm a little confused about the set20, as it's an option over on the Wilwood site for the Torino ends. I guess among other things I need to get some more details as to what they think about my different options.

Matt (Jones), thanks for the Currie plate link. I think I saw you post that in the other knock back thread. I almost posted this here but also wanted to bring up the seal leak issue, which is why I started the new thread. The only issue with the full circle retainer is that my understanding is that I'll need to replace my axles, and could have them shipped from Moser with bearings pressed on. They're probably not going to be too crazy about sticking a set of Currie plates on there first. I could just order them without the bearings pressed on and do it separately. One thing I'll need to figure out if I press them myself is exactly what depth they need pressed to, right? I want to make sure I do NOT mess with my track width.

[wmhjr]

BTW, between Matt sqaured and John, you guys have convinced me to move to a tapered bearing. Isn't it wonderful how people here can help spend money!

[Larry Callahan]

Wilwood solved mine with a floating caliper. The caliper is now for sale but supposedly MotiV8r has the only prototype production bracket. So far it works awesome!

[wmhjr]

I have a call in to Mike Hamrick at Wilwood to discuss this. Hopefully I'll hear back before long.

[silver69camaro]

My retainers dont compress the lip, they actually have a step in them. Matt do you have the dimension from bearing seat to outer housing end where the retainer mounts? I was always worried about flipping the retainer and putting to much pre-load on the bearing. When the bearing is new and the outer seal has not seen the track I have .015 to .020 end play. After track time is will slowly increase depending how many track days I complete.

You need to have the retainer's lip towards the seal/bearing, and there should be zero end play. Don't worry about putting too much preload on that bearing, more is better. From inside bearing seat surface to the outer housing end face is 0.675" for most housing ends.

Also, you shouldn't need to axles with the Currie retainer. Just press off your old bearings, slide the retainer over the shaft (lip side in!), and press the new bearings on. Do your current axles have stops machined on the shaft for the bearings? Most will have a positive stop so you can't screw it up.

[Ron S]

I have the same issue with my Mustang. In fact it is so bad that as soon as I come out of the turns on the the road courses I have to set the brakes so that the next turn won't be so scary. Its funny you kind of get used to it, but the first couple times at over 100 mph you almost sh*t yourself.

I've tried everything to tighten them up, the tapered bearings don't help much and require different housing ends. A floater is the only real answer. I really hate 9" rears, I am doing a Dana 60 floater for the AMX I'm building, for now I'm just going to live with the problem in my Mustang. Ron

[Van B]

No thread hijack intended here but this thread got me thinking. I had a fab guy I know install my 4 link last year and he also built a 9" housing for me. I have also experienced seal leakage (see thread link below) and brake knockback. This morning when reading this I started thinking about a residual pressure valve, but now I am thinking I have something bigger I have to fix. You can see by the pictures that the caliper mounting bracket holds the axle and seal in the housing but the spacers on the t bolts trouble me and make me think that the axle may have a lot of play and causing the knockback.

Share your thoughts and maybe we all can learn from it.

https://www.pro-touring.com/showthread.php?80709-9-inch-axle-seal&highlight=

[Vegas69]

I've went around the world on this deal.

Moser 12 bolt, big ford ends, 33 spline, true trac, roller bearing(to start), 7/8 manual, 13" sl4 calipers, original wilwood plates=Knock back was unbearable and pump brakes city.

1. I found that the Wilwood bearing plate had approx. .010-.020 free play between the bearing and plate. Called Wilwood and Moser and told them to take their head out of there you know what..... I am the reason Wilwood made the new plate way back when.
2. OK, found out Currie made a full circumfrance thick plate and installed. Made very little differernce.
3. Switched to tapered bearings, cut it down by approx. 40%.
4. Put in a 2 psi residual valve, didn't do a damn thing but cost me 20 bucks.
5. Changed to a 1" bore master cylinder. Helped again and cut it by another 20-25%.
6. Shimmed the inside of the bearing races to tighten up the bearings. Didn't notice any difference but I only added .020 in fear of to much preload.
7. Lived with it for a long while but the bearings began loosening up and the knockback gradually got worse.

Like Larry, I also adapted Wilwoods brand new GM floating metric caliper to an internal parking brake set up with a top secret bracket NOT made by Wilwood. I had to go to the 12.2x.81 rotor to make this happen. Brake knockback is 100% gone on the street and still a hint in autocross. Brakes are by far the best they have ever been on the track. Here's the deal, I overheated my front brakes at Pomona two weekends ago running 8 or so speed stops in a row. You don't need these massive rear brakes on a pro touring car. Look at a C6 corvette of C5 Z06 for a moment. There is a reason 98% of factory cars come with floating calipers on the rear axle. hmmmmmmmmm

I also want to say Dustin Burr at Wilwood really helped me out and really helped make the Metric caliper a reality. I don't blame Wilwood for my problem, I made an engineering mistake by using a part in the wrong application.

I will say that my big wheel lip has likely made mine worse along with r888's and I've got my car working pretty decent. Bottom line for me, I'll NEVER build another car with a fixed caliper out back without a floating axle or caliper. I'll also never build another car without a real Ford 9". I think the whole 12 bolt with 9" ends plays into the deal in some instances from all the guys I've talked to over the years. End of story.........

[rsk68]

Only real fix is floating axles or calipers, floating calipers are limited to one or two pistons and is my temporary fix for now, I will be going floating axles in the future.

[wmhjr]

So I talked to Mike at Wilwood last night. Here is my current plan at a high level.

First, I'm moving to tapered bearings, and while I'm at it I'm planning to use the Currie full circumference retainer. It's 1/4" and all the way around so it should make the axle retention as good as it can be. I'll also measure the runout and if necessarly, shim the assembly so that I can get a good amount of preload. Hopefully these steps will eliminate the leaking, and stabilize the movement as much as possible. I'm not sure yet as to the details of swapping the sealed bearing for the tapered bearing, as Moser indicated yesterday that my existing axles as is cannot handle the tapered bearing. I'll find out more details on that.

As for brakes, I'm going to try the wilwood floaters in the back after getting the input from you guys and talking to Mike at Wilwood. There are two piston sizes and I'm planning on using the larger one as currently my prop valve (bias) is wide open with my 14" SL6s up front, 12.2" Dynalites in back, and a 7/8" master. Mike indicated that he would get back to me about bracket timing but thinks we can make this work pretty quick.

Currently I'm like Ron. At Gingerman I was REAL surprised the first time I came accelerating out of a turn and hit my brakes at 100mph+. Good thing we had familiarization laps. At Autobahn, it was a litte better, probably because I swapped the old "thinner" retainers which provided zero bearing preload for the newer ones (on Friday night at the host hotel parking lot) :)

The real problem was the Autox. At motor state, let's just say that the finish line was always interesting for me. The roadster shop should probably have moved their rig..... At Heidts, it was kind of a good news, bad news thing. The bad news was that there was so much more dramatic left/right stress that I virtually had no brakes most of the time. The good news was that since I never got out of 1st gear (as opposed to starting and staying in 2nd at motor state) that I could mainly use the throttle - EXCEPT for that one last hard right turn before the smoking left hander to the finish.

I really appreciate the advice here, guys. This is a good topic. I'm probably the poster child for this issue, as I have a long, heavy, live rear axle big body car being thrown around on an Autocross, and I have a lot of torque to the ground. If I can get this improved sufficiently then it ought to work for anybody.

[Bow Tie 67]

Sounds like a good plan, I tried flipping my retainer but thats a NO-GO, so looks like I will be shimming behind the race in the housing end. Here are some pics of what my setup looks like.

https://static1.pt-content.com/images/noimg.gif (http://good-times.webshots.com/photo/2576302620065608932CYIqbR)

Here you can see the retainer step lip

https://static1.pt-content.com/images/noimg.gif (http://good-times.webshots.com/photo/2541620000065608932FRZpiV)

I believe the retainer is a BAER part, but I'm not positive, it came with the car

https://static1.pt-content.com/images/noimg.gif (http://good-times.webshots.com/photo/2559399820065608932lWMBoN)

Bill here is the set20 setup with the race removed from the housing and laying on the red rag

https://static1.pt-content.com/images/noimg.gif (http://good-times.webshots.com/photo/2033010310065608932YNdCSI)

[Ron S]

The real problem was the Autox. At motor state, let's just say that the finish line was always interesting for me. The roadster shop should probably have moved their rig.....


Amen, a few times I almost screamed for the flagger to get out of the way. Mine was a handful in that same spot. I hate to say I've grown used to it, but I think I have. VIR should be exciting this weekend. Ron

[Vegas69]

What caliper are you considering? The GM metric Larry and I used comes in 3 piston sizes.

I also had to buy new axles as my roller axles wouldn't work. After I recieved the tapered bearing axles, I had to send them back to get turned down because the offset didn't match. I still think Wilwood and Moser didn't get on the same page in the infancy of this whole movement.

[TheJDMan]

It seems to me that a lot of people spend a lot of time fussing over this pad knockback issue. The only real solution is floating hubs and there are a couple of ways to get them for not a lot of money. If you want to keep your current rear end, for about $450 you can buy a floating hub kit from Moser which can be welded into your existing housing and Moser can then build you a set of custom axles for about $150. Or in my case, I sold my 12 bolt which paid for the purchase of a new Moser 9" housing with floating hubs and axles for $879 and I still have money from the 12 bolt sale to apply to the purchase of a center section. Figuring what I sold the 12 bolt for and the cost of the Moser 9" floater housing and a center section, it will end up costing me about $150 for the switch. I just don't see the point of spending all this energy on a marginal design for such a high performance application. Obviously John sees the advantage of floating hubs since he is using them on Unfair.

[wmhjr]

Moser can make a set of custom axles for $150? They want $500 for my current axles.

[TheJDMan]

Actually I misquoted the price they are actually $178pr. Floating hub axles are much less expensive than the conventional axles presumably because they are much easier to manufacture. Check out Moser's web site and look in the Circle Track section. Floating hubs are not nearly as expensive as most people think. If you are spending $500 on axles you could be converting to floating hubs for not a lot more.

Here is another good source of floating hub parts.
http://9inchfloater.com/

[parsonsj]

Obviously John sees the advantage of floating hubs since he is using them on Unfair.Why yes, yes he does. It's the best way to get 0 knockback. (and just a minor quibble: it's the axles that float, not the hub)

I must point out that the only knockback I experienced with II Much was when I had a bad front bearing. I fixed that bearing and never noticed any knockback after that. My setup on that car was a 9" Ford, 35 spline Locker, Set20 axle bearings, Moser axles, and ordinary Wilwood 12" rear disc brakes. I even used the Wilwood U-shaped axle retainer. At autoX events, I battled power steering woes, and fuel pump cavitation, but never knockback. It is possible to eliminate knockback (to the point where one doesn't notice it) without going to a floater setup.

[Vegas69]

It seems to me that a lot of people spend a lot of time fussing over this pad knockback issue. The only real solution is floating hubs and there are a couple of ways to get them for not a lot of money. If you want to keep your current rear end, for about $450 you can buy a floating hub kit from Moser which can be welded into your existing housing and Moser can then build you a set of custom axles for about $150. Or in my case, I sold my 12 bolt which paid for the purchase of a new Moser 9" housing with floating hubs and axles for $879 and I still have money from the 12 bolt sale to apply to the purchase of a center section. Figuring what I sold the 12 bolt for and the cost of the Moser 9" floater housing and a center section, it will end up costing me about $150 for the switch. I just don't see the point of spending all this energy on a marginal design for such a high performance application. Obviously John sees the advantage of floating hubs since he is using them on Unfair.

That's really easy for you to say now. You would think it was apparent but clearly it's not since it seems to be a big issue around this community. Please keep in mind that many of us started building these cars 4,5,10 years ago. When I started experiencing this problem in 2008, I felt like a lone wolf and was on my own to figure out a fix. Now, as projects continually hit the road, more people are coming out of the woodwork. Personally, I would need to rehoop my rims to run a moser floater set up and I'm not crazy about the maintenence involved with a floating axle. I'm happy with my floating calipers and I'll move on to greener pastures.

[wmhjr]

It seems to me that a lot of people spend a lot of time fussing over this pad knockback issue. The only real solution is floating hubs and there are a couple of ways to get them for not a lot of money. If you want to keep your current rear end, for about $450 you can buy a floating hub kit from Moser which can be welded into your existing housing and Moser can then build you a set of custom axles for about $150. Or in my case, I sold my 12 bolt which paid for the purchase of a new Moser 9" housing with floating hubs and axles for $879 and I still have money from the 12 bolt sale to apply to the purchase of a center section. Figuring what I sold the 12 bolt for and the cost of the Moser 9" floater housing and a center section, it will end up costing me about $150 for the switch. I just don't see the point of spending all this energy on a marginal design for such a high performance application. Obviously John sees the advantage of floating hubs since he is using them on Unfair.

Seems to me that you're pretty significantly understimating the cost. Looking at the Moser site, their floaters are designed for 40 spline axles. So, essentially my entire rear end gets replaced, right? That's a bit more than "ending up costing me about $150 for the switch". It's extremely unlikely to the point of being flat impossible that this will happen to me. At a rough guess, I'd say that my outlaw would be a minimum of $2K all in, assuming I can find somebody who will pay a good price for my existing rear end. I also then need to consider rehooping two - not one - sets of rear wheels.

I also understand that if I were buildling today, I'd probably put a different rear end under the car than I currently have - but I bought this one in 2008. I'm looking for a cost effective solution that eliminates as much as possible of the issues without creating undue maintenance/complexity and cost - while also minimizing how much time I'll lose use of the car.

That being said, I'm asking for advice and I will certainly talk to Moser about this option to find out what they think. I just know that in my geographic area, it's going to be tough in these times to even remotely consider getting decent money out of my existing rear end - which other than the leaks and the knockback, has been excellent.

[wmhjr]

Sounds like a good plan, I tried flipping my retainer but thats a NO-GO, so looks like I will be shimming behind the race in the housing end. Here are some pics of what my setup looks like.


Matt,

Thanks for the pics. They help.

[wmhjr]

What caliper are you considering? The GM metric Larry and I used comes in 3 piston sizes.

I also had to buy new axles as my roller axles wouldn't work. After I recieved the tapered bearing axles, I had to send them back to get turned down because the offset didn't match. I still think Wilwood and Moser didn't get on the same page in the infancy of this whole movement.

I'm not completely sure yet. I don't know if it's the GM-III or the metric. I believe it's the larger of the piston sizes, but it's still early and I don't have enough details yet.

[pedro]

I'm not crazy about the maintenence involved with a floating axle. I'm happy with my floating calipers and I'll move on to greener pastures.

What additional maint is required for a floating axle compared to a normal one?

Pete

[wmhjr]

What caliper are you considering? The GM metric Larry and I used comes in 3 piston sizes.

I also had to buy new axles as my roller axles wouldn't work. After I recieved the tapered bearing axles, I had to send them back to get turned down because the offset didn't match. I still think Wilwood and Moser didn't get on the same page in the infancy of this whole movement.

OK, got at least a little clarification. It's the D154 GM Metric in 1.62" piston sizes.

[TheJDMan]

First off, floating hubs are not new technology, they have been used in circle track racing and NASCAR for years. So just because someone's build is 10 years in the making, floaters were readily available back then too.

Yes Moser sells 35 and 40 spline axles but you need to look at Moser's Circle Track secition again. For $89ea they also sell either 28 or 31 spline floating axles your choice. http://www.moserengineering.com/circle-track-packages-and-parts/moser-ct-axles.html

A complete Moser 9" bare Floater housing kit includes everything you need to build a complete rear end minus a center section for $879 in any width you specify. As for rehooping wheels, I don't know what you are basing that assumpton on?

11", 12" and even 13" brake rotors are readily available for floating hubs and as John can attest 14" brakes are also possible with the right adaptor. BTW, I am sure some vendor will offer the 14" rotor adaptor that John used soon which will bring that cost down significantly.

Bottom line is you guys that are really hard core PT have probably spent more time and money messing around with conventional style axles to have paid for a floater rear end several times over.

Oh, and Moser is not the only supplier of floating rear ends, hubs and axles. Here is another popular supplier. http://www.9inchfloater.com/index.htm

[wmhjr]

First off, floating hubs are not new technology, they have been used in circle track racing and NASCAR for years. So just because someone's build is 10 years in the making, floaters were readily available back then too.

Yes Moser sells 35 and 40 spline axles but you need to look at Moser's Circle Track secition again. For $89ea they also sell either 28 or 31 spline floating axles your choice. http://www.moserengineering.com/circle-track-packages-and-parts/moser-ct-axles.html

A complete Moser 9" bare Floater housing kit includes everything you need to build a complete rear end minus a center section for $879 in any width you specify. As for rehooping wheels, I don't know what you are basing that assumpton on?

11", 12" and even 13" brake rotors are readily available for floating hubs and as John can attest 14" brakes are also possible with the right adaptor. BTW, I am sure some vendor will offer the 14" rotor adaptor that John used soon which will bring that cost down significantly.

Bottom line is you guys that are really hard core PT have probably spent more time and money messing around with conventional style axles to have paid for a floater rear end several times over.

Oh, and Moser is not the only supplier of floating rear ends, hubs and axles. Here is another popular supplier. http://www.9inchfloater.com/index.htm

Steve, you are really missing the point. And I talked directly with Matt at Moser today. The point is that I currently have a Moser 12 bolt w/Truetrack, 33 spline axles, brakes, rotors, etc. Moving to a floater means replacing everything. Everything. Is it possible that over time I could sell some of what I have? Sure. These days, at a pretty steep discount. I would need to replace every darned part of that entire rear end. I fully agree (as mentioned before) that if I were starting from scratch, I would definitely go with floaters. However, I STRONGLY disagree that floaters were "readily available" for many people. What I mean is that when I started building, I wasn't really thinking about high side loading and frankly had never even talked about knock-back in my life. It sounds easy in hind sight. So does investing in Berkshire Hathaway in 1962.

As for rehooping, the issue is offset and backspace - and the geometry of the floater. It seems very likely that because the hub to rotor measurement of the floaters I've seen (doesn't mean they're all that way, but....) is larger than my current setup, the axles will need to be cut and the snouts welded on creating a different (wider) track width, requiring additional backspace, as I have no room whatsoever for moving the tire/wheel inboard/outboard within the wheel houses. Not definite, but it seems as though I'm not the only one that has encountered this.

Bottom line is that I'm not trying to build a new car. I'm trying to maximize the performance of the major components I have. I appreciate the advice but still think you're SERIOUSLY understating the cost and degree of change to move to a full floater setup.

[Flash68]

I think you're both making good points actually. Some things I see here and overall:

Conversion costs are not always as simple and straightforward as "budgeted"

99% of "Pro Touring" guys are not really pushing their cars hard. Most do not attend the various (most excellent!) events around the country. Even within that small group, only some are really driving their cars hard and at the limit to induce things like pad knock back. I am pushing mine as hard as can be humanly done and TRYING to induce knock back but it's only slight thus far, thankfully.

Only in recent years with the help of these RTTX and type events have more and more really flogged their cars and induced these issues. So even though they might have been available via circle track or nascar sources, that has not been the normal place for "PT" car guys to shop or even look for. A lot of this has been just following in the footsteps of the previous build or what Shop ABC installed.

IMO, it all boils down to being great for the advancement of the PT niche that is truly taking their cars to the next level and trying to upgrade performance and extract that extra bit they are wanting. I think the biggest catalyst for pushing this type of stuff has been these performance events that create competition and get the competitive juices flowing.... in some people that might not even anticipated it. I see cars on these forums that have just been cruisers for years now getting to events and track days and I think that is great. And threads like this result from it, which can benefit a lot of people.

Good talk, Rusty. :)

[TheJDMan]

In my case, I sold my old 12 bolt for $1400. Turned around and purchased the Moser 9" CT rear end with a 57" width to fit my existing 18x12 Forgelines for $879. I found an ebay seller offering custom rebuilt 9" center sections for $650 in any gear ratio I choose. http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&_trksid=p4340.m748&item=330590099558&viewitem=&_trkparms=clkid%3D1532138242192626805 Now admitidly the $650 center section is not a Noduler or Alum housing but at that price I can have a strong street rear end and always upgrade later. The 12 bolt had drum brakes so I would have the brake upgrade expense for either rear end so that is a wash. Bottom line, it cost me less than $150 to do the swap.

[Vegas69]

Steve, apparently you know everything. Next time I have a problem, I'll be sure to PM you. ha ha I'm assuming you didn't learn about a floating axle in a dream. You must have grown up around higher end race cars or learned it from experience. Did you bother to post your fix for the world to see?

Moral of the story is that many of us created our own destiny with a mismach of parts and big time leverage with the large offset.

[TheJDMan]

Steve, apparently you know everything. Next time I have a problem, I'll be sure to PM you. ha ha I'm assuming you didn't learn about a floating axle in a dream. You must have grown up around higher end race cars or learned it from experience. Did you bother to post your fix for the world to see?

Moral of the story is that many of us created our own destiny with a mismach of parts and big time leverage with the large offset.

No need to be insulting! If you're not interested in learning why are you here?

[Vegas69]

Pot calling the kettle black, pal. You come in here with the attitude that we should've known better. If you knew your head from your ass, you would know that I'm the first guy to tell ANYONE everything I know and appreciate any knowledge a member is willing to pass on. You should post up a thread with pictures and parts that you used to fix your problem. I see you started a thread on Lateral-g. That would be a great start.

[wmhjr]

In my case, I sold my old 12 bolt for $1400. Turned around and purchased the Moser 9" CT rear end with a 57" width to fit my existing 18x12 Forgelines for $879. I found an ebay seller offering custom rebuilt 9" center sections for $650 in any gear ratio I choose. http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&_trksid=p4340.m748&item=330590099558&viewitem=&_trkparms=clkid%3D1532138242192626805 Now admitidly the $650 center section is not a Noduler or Alum housing but at that price I can have a strong street rear end and always upgrade later. The 12 bolt had drum brakes so I would have the brake upgrade expense for either rear end so that is a wash. Bottom line, it cost me less than $150 to do the swap.

OK, so for your numbers to work, here's what would need to happen for me. First, I'd have to find somebody locally who would be ready and willing to pay me less than half of what my Moser setup cost me. Then, I'd have to find a floater setup that has a inside brake caliper/rotor to hub mounting surface measurement that will allow both my 18x10s to fit - AND for there to be the exact same track width, AND that the inside of the caliper/rotor is not moved inboard at ALL as this would both totally screw up my suspension and I have zero extra clearance. Frankly, it's far more likely that the track width would have to change as there is not sufficient room outside of the LCA mounts to begin with to allow this to happen at a guess. But let's say that happens. I then have to be OK with going with an eBay center section that would clearly not be as strong or have the support that my current setup provides - not for "strong street driving" but for TRACK driving. Because I DON'T have rear drums, I am also forced into a completely different brake setup.

I also lose the ability to even move the car (roll it) for at least a month and probably more. Since I know of two (2) 12 bolt rears and a 9" for sale right now by friends locally, I'm not real optimistic that I'm getting the cash for mine anytime soon.

Steve, I understand and agree that a floater would be an excellent option. Who knows? Maybe down the road I'll go that way. But it's clear to me that there are MANY variables here and that there is zero possibility that I would end up with a similar quality, tough, assembly for even ten times your $150 total outlay. This is more of a winter project to me, where there is time and no near deadlines so that progress can continue. Hope this makes sense. Not everyone is running an "old 12 bolt" with drum brakes.

[sik68]

Very interesting thread...I have knockback issues too, and have been making some of the cheap, basic changes to mitigate it. Fortunately I am running the original 8.2" 10 bolt, so I won't feel so bad about upgrading down the road. Looks like full floater is something to consider for me.

On the track, I pump the pedal 2x with my left foot before every big braking zone. I get a good pedal this way, and I think even if I didn't have knockback issues, I like touching the brake to confirm the they are going to be there for me. I think it's a good habit to develop regardless. For autox though, knockback does become a lot worse, and it's harder to find time to pump the pedal up. But I left foot brake in autocross so I'm pretty much pumping or braking the entire time, ha.

Leading question: anyone knowledgeable about the current generation S197 mustang setup? It looks like they're not floaters, and for all of the track cars out there I haven't heard a word about knock back.

[Vegas69]

You will eventually wear out the bore of your master cylinder pumping brakes. I destroyed my 7/8 master. Make sure you keep a close eye on your brake fluid. A floating caliper is just the most economical repair. After selling my SL4 kit, I broke even or made a few bucks.

One of the main reasons I never switched to a floating caliper was the availability of a matching and good looking caliper. I'm just not a fan of the baer corvette caliper. Also, I wanted to keep my internal parking brake. I use my parking brake all the time and it works fantastic. Wilwood's metric caliper changed the game for me. It looks great and I kept my parking brake.

https://static1.pt-content.com/images/pt/2011/07/BackBrakes010-1.jpg
https://static1.pt-content.com/images/pt/2011/07/BackBrakes009-1.jpg
https://static1.pt-content.com/images/pt/2011/07/BackBrakes002-1.jpg
https://static1.pt-content.com/images/pt/2011/07/BackBrakes001-1.jpg

[BADDRIDE II]

OK, so for your numbers to work, here's what would need to happen for me. First, I'd have to find somebody locally who would be ready and willing to pay me less than half of what my Moser setup cost me. Then, I'd have to find a floater setup that has a inside brake caliper/rotor to hub mounting surface measurement that will allow both my 18x10s to fit - AND for there to be the exact same track width, AND that the inside of the caliper/rotor is not moved inboard at ALL as this would both totally screw up my suspension and I have zero extra clearance. Frankly, it's far more likely that the track width would have to change as there is not sufficient room outside of the LCA mounts to begin with to allow this to happen at a guess. But let's say that happens. I then have to be OK with going with an eBay center section that would clearly not be as strong or have the support that my current setup provides - not for "strong street driving" but for TRACK driving. Because I DON'T have rear drums, I am also forced into a completely different brake setup.

I also lose the ability to even move the car (roll it) for at least a month and probably more. Since I know of two (2) 12 bolt rears and a 9" for sale right now by friends locally, I'm not real optimistic that I'm getting the cash for mine anytime soon.

Steve, I understand and agree that a floater would be an excellent option. Who knows? Maybe down the road I'll go that way. But it's clear to me that there are MANY variables here and that there is zero possibility that I would end up with a similar quality, tough, assembly for even ten times your $150 total outlay. This is more of a winter project to me, where there is time and no near deadlines so that progress can continue. Hope this makes sense. Not everyone is running an "old 12 bolt" with drum brakes.

Just wanted to plant another option in support of "Full Floaters"......why not keep your existing housing/gearset/etc./brakes & possibly even your axles. This is how.....from what I know of my floater setup (GMR), you would simply cut your housing ends off at necessary location and weld in the new snouts (this should be done with correct fixturing though), I see NO reason (although not impossible) why you would not obtain exact wheel mount surface as before (therfore utilizing existing wheels/tires). As for the GMR floater hub kit, the cut point on the axle tube for the snout/spindle install is at precisely 5" from your desired wheel mount surface. So basically if you measured from your current WMS back 5", and it does not interfear with suspension bracketry/etc. (which is highly unlikely) you would most likely be a go for the GMR floater kit if desired, and with the offset wheel you are currently running you would be fine up to a 14" rotor/caliper with your 18" wheel. Now as for the Moser kit that Prodigy and others have mentioned, it may not fit as its wheel mount surface to rotor distance seems far wider than that of GMR and may become a problem with existing suspension bracketry or even wheel tub to caliper clearance? As for salvaging your brakes, the GMR kit includes a Rotor Adapter made so you can use either new, or in your case existing rotors so long as they are 12x 8.75 bolt pattern rotors as Wilwood or (I think they offer 12x 8.5 for Baer as well?). You are also able to utilize your existing caliper as well so long as they are currently radial mount style? (sorry you may have mentioned exactly what brake setup you have, but the thread is too long to read back again to absorb all that has been said). As for the axles I am not sure......but obviously your carrier spline currently would be correct already, and I am thinking the axle itself would be long enough even once existing axle flange was cut off (not sure though...just brain storming) and it then would just need to be broached/splined correctly. So in closing I will be the first to say this is by NO means the cheap way out when done right, but merely a suggestion for people wanting to salvage what they can if converting to "Full Floater". In most cases I see the "conversion" costs to be: Floater Kit Cost + Floater Snout Install + New Axles (unless existing ones are long enough and then it would just be broaching cost) + Caliper & Caliper Bracket (unless you already have radial mount style calipers and in that case you would only need caliper bracket) So the reality is...even salvaging the "assumed" components of axles/calipers, I still see you spending approx. $3000 on Floater Kit & Install/Caliper Brackets (now keep in mind this is based on GMR's kit costing just under 2K which is pricy but well worth it in my opinion) The circle track floater kits on the market like Mosers & nine inch floater dot com are far less in cost, but do not even come close in strength/weight/overall design. If you are going to commit to a floater and really use it, you may as well do it right the first time and buy the best component available. Well hope this helps you or even future readers of this thread. Keep us posted. Good luck! :cheers:

[BADDRIDE II]

Quick update......I do not believe the axles will work once cut, most likely will be too short :(.....so the projected approx cost of $3000 stands assuming your Calipers are radial mount type. Thanks for listening. :rolleyes:

[carguy502]

You will eventually wear out the bore of your master cylinder pumping brakes. I destroyed my 7/8 master. Make sure you keep a close eye on your brake fluid. A floating caliper is just the most economical repair. After selling my SL4 kit, I broke even or made a few bucks.

One of the main reasons I never switched to a floating caliper was the availability of a matching and good looking caliper. I'm just not a fan of the baer corvette caliper. Also, I wanted to keep my internal parking brake. I use my parking brake all the time and it works fantastic. Wilwood's metric caliper changed the game for me. It looks great and I kept my parking brake.

https://static1.pt-content.com/images/pt/2011/07/BackBrakes010-1.jpg
https://static1.pt-content.com/images/pt/2011/07/BackBrakes009-1.jpg
https://static1.pt-content.com/images/pt/2011/07/BackBrakes002-1.jpg
https://static1.pt-content.com/images/pt/2011/07/BackBrakes001-1.jpg

Is that thing a wilwood kit or some kind of floating conversion on an existing kit?

[TheJDMan]

The GMR kit is overpriced by at least $1300 before the axles. The GMR kit uses a propriatary 35 spline axle drive plate that no one else makes which means you have no other source for the axles than GMR. The Moser floater is an aluminum housing with a steel driver plate and industry standard 24 spline drive and sells for $450 and the axles are $89ea. The 9" Floater 28/31 spline hub kit is all steel, sells for $400 and also uses an industry standard 24 spline drive plate. Both Moser and 9" Floater units are used in racing applications and have been for 30 years or more. Granted both Moser and 9" Floater have an 8 on 7" rotor adaptor but for well under $1300 any competent machine shop can build bigger rotor adaptors or Wilwood sells a 13" rotor that will fit the 8 on 7" adaptor. GMR advertises stainless steel propriatary studs which means if you strip a thread or cross thread a nut you have to go back to GMR to buy replacements at who knows what price assuming they are still in business years down the road when you need parts. I also have to question the use of SS for wheel studs, what is wrong with grade 8 studs.

Bottom line is that GMR is a new product with no history, propriatary parts and way overpriced.

As for determining how wide the axle housing needs to be cut, I went to the local muffler shop and had them make me up a section of 3" exhaust pipe tubing. I then inserted the hub snouts in each end and bolted the wheels on the hubs and mocked up a rear housing to get an accruate width. Attached is a picture of the exahust tubing with the hubs inserted and placed under the car that I used for measurements.

https://static1.pt-content.com/images/pt/2011/08/camaro20019-1.jpg

This is the Moser rear end during the installation.

https://static1.pt-content.com/images/pt/2011/08/camaro20034-1.jpg

As pictured above, I have $879 in the Moser rear end housing, of course that does not include the G-Link suspension and I welded on the brackets myself.

[wmhjr]

Steve, thanks but you're still seriously underestimating the cost of change. And you're not accounting for the already mentioned possibility that the offset change (rotor to flange) could result in needing to rehoop regardless be use it could force a track width change. Some of us already have brakes, and the caliper change is minor.

Anyway, this is great info that I wish I'd have had when I was building, but isn't something I'm going to do now.

[parsonsj]

Let's criticize arguments, not persons, please.

[The GMR]

The GMR kit is overpriced by at least $1300 before the axles. The GMR kit uses a propriatary 35 spline axle drive plate that no one else makes which means you have no other source for the axles than GMR. The Moser floater is an aluminum housing with a steel driver plate and industry standard 24 spline drive and sells for $450 and the axles are $89ea. The 9" Floater 28/31 spline hub kit is all steel, sells for $400 and also uses an industry standard 24 spline drive plate. Both Moser and 9" Floater units are used in racing applications and have been for 30 years or more. Granted both Moser and 9" Floater have an 8 on 7" rotor adaptor but for well under $1300 any competent machine shop can build bigger rotor adaptors or Wilwood sells a 13" rotor that will fit the 8 on 7" adaptor. GMR advertises stainless steel propriatary studs which means if you strip a thread or cross thread a nut you have to go back to GMR to buy replacements at who knows what price assuming they are still in business years down the road when you need parts. I also have to question the use of SS for wheel studs, what is wrong with grade 8 studs.

Bottom line is that GMR is a new product with no history, propriatary parts and way overpriced.




Im sorry about the pricing, I was unaware that our pricing structure would be so offensive to some individuals. We have a set pricing structure because our investment cost is well above the competition. I set out to manufacture products that are of the up-most in quality first, with being cheap the last consideration. If I were to produce products that are in the same realm as Moser and 9 inch floater then I would be just another follower. GMR is not a follower.

My intention was to create top shelf quality, not bottom shelf pricing. Again, I'm sorry if you find offence in this, it was not my intention.

Either way, thanks for taking the time to at least review our product offering. I want to clear up a few quick things. The items you address are not exactly congruent with the truth, please take some time to better review our product or better yet, please give me a call at the office. I would be more then happy to answer any questions or concerns you may have.


P.S. - We can also discuss that caliper bracket you inquired about. I can have something drawn up in CAD within minutes then email you some rough drafts before anything is even cut.
714-596-8800
Thanks for your time.
Jason

[TheJDMan]

I want to clear up a few quick things. The items you address are not exactly congruent with the truth, please take some time to better review our product or better yet, please give me a call at the office. I would be more then happy to answer any questions or concerns you may have.

Jason,
By all means clear up anything I wrote that is incongruent with the truth! I have no intention of passing on false information.

The fact is that floating hubs have been used in many forms of auto racing for probably 30 years. In that time the design of the floating hubs has been, what most would consider, throughly tested and proven. Floating hubs have become so popular/common among racers that over the years a number manufacturers have entered the market in order to supply the demand. All of them, to the best of my knowlege, have standardized on 24 spline drive plates in both Grand National and Sportsman style hubs. This standardization has resulted in a lot of competition between manufactures which in turn has driven up the quality and driven down the prices. The biggest benefit to us homebased PT builders is that you can now buy any number of strong, high quality, American made floating hub kits/rear ends for very reasonable money. The design of floating hubs makes it a natural choice for PT cars. My intent has been to educate members on the cost/value of floating hubs on a street/track PT car.

Make no mistake, I am not offended by GMR's NEW floating hub offering. The GMR hub is unquestionably a high quality product with a significant number of proprietary components and a lot of bling at a premium price. It will be right at home in high end, high profile builds. But proprietary parts are not necessarily a good thing and offer questionable functional advantage over the Moser, 9" Floater or Speedway Engineering floating hubs just to name a few. For the vast majority of little guys like me building my PT car on a tight budget, the GMR hubs have no place in my build when I can get the same American made quality and proven performance of floating hubs for 1/3 the money.

My goal here was simple, to inform you guys like me here on PT fighting pad knockback about the advantage of running floating hubs without spending a small fortune. I never intended this to become product review.

[MoparCar]

JDman,

Do you have any pictures/details of your brake mounts or brakes installed? What are you running for brakes?
Thanks-Wes

[wmhjr]

So, since I'm the OP I thought I would update on status.

Am going with tapered bearings (Timken SET20) and seals, as well as Currie retainers, and Wilwood D154 GM floater calipers on my existing wilwood brake setup (with modified brackets from Wilwood).

As of last night, I now have the retainers and seals on the axles, and the SET20 bearing/seal combination pressed on to the axles. They are ready to go on. Need to talk to Wilwood today about exactly what measurement they need for the bracket and will then mock up the assembly and take measurements for them.

[Matt@BOS]

Jason,
By all means clear up anything I wrote that is incongruent with the truth! I have no intention of passing on false information.

The fact is that floating hubs have been used in many forms of auto racing for probably 30 years. In that time the design of the floating hubs has been, what most would consider, throughly tested and proven. Floating hubs have become so popular/common among racers that over the years a number manufacturers have entered the market in order to supply the demand. All of them, to the best of my knowlege, have standardized on 24 spline drive plates in both Grand National and Sportsman style hubs. This standardization has resulted in a lot of competition between manufactures which in turn has driven up the quality and driven down the prices. The biggest benefit to us homebased PT builders is that you can now buy any number of strong, high quality, American made floating hub kits/rear ends for very reasonable money. The design of floating hubs makes it a natural choice for PT cars. My intent has been to educate members on the cost/value of floating hubs on a street/track PT car.



Just curious, have you ever used one of these companies' floater setups? And if so, how recently? I had a friend with a Moser floater (maybe 10 years ago) and apparently it was basically crap. I have to wonder if quality has gone up in recent years. I've seen several builds on here use Moser's floater, but haven't heard feedback from anyone within the community.

Matt

[gearbanger]

I am learning alot from this thread. Maybe the reason I have never felt the knockback issue is that I have never had anything but floating caliper setups. I have thought about what is going on alot and never could figure out how a miniscule amount of flex in my axle flanges or spindle pins could be causing enough knockback to even feel much less to have to double pump my master cylinder. My calipers are probably taking up all that flex without actually moving the caliper pistons.

That makes me happy that I went with the C5 brakes!

[TheJDMan]

JDman,

Do you have any pictures/details of your brake mounts or brakes installed? What are you running for brakes?
Thanks-Wes

I have not purchased brakes yet. I'm still trying to decide between Wilwood, Baer or Corvette Z06 brakes. BUT, here is a great set of pics of the floating hub and rear brake setup.

https://www.pro-touring.com/showthread.php?44130-Satan-s-quot-Lady-Bug-quot&p=789544#post789544

[parsonsj]

Bill's got a direction, and the thread continues to sit on the edge of going south, so that's all for now.