Who makes A Body aluminum mounts? Pro- Cons

[Addicted]

I have a set of mounts that are supposed to be for a 70 chevelle , but all the mounts are the same size and the car sits up off the rear ones. I could shim but really dont want to. Seems that everyone is PT these cars so i would have figured that these body mounts would be common? Do they affect the ride quality that bad that people are not doing this? Any comments or a vendor with a set would be nice.

Thanks

[shep]

Latenight72 made a few sets they were fairly reasonable but he only sold a couple sets. So he sold the last few and said he wouldn't make any more. other than that nobody makes them.

[Addicted]

What is everyone doing as far as mounts, then?

[Tiger]

I'm using poly for my Chevelle

[MarkM66]

Really, aren't poly damn near solid?

I really don't see those things deflecting much, especially after being wedged between the body and the frame.

[raustinss]

i wouldnt use them as i ve been told they will give a VERY stiff ride ...just use the stock rubber or after market poly

[wmhjr]

Using Poly.

[John Wright]

i wouldnt use them as i ve been told they will give a VERY stiff ride ...just use the stock rubber or after market poly
(not picking on you, just used your quote)

I've heard this told many times, but I don't see how they can affect the ride. They are simply sandwiched in between the body and frame...and have nothing to do with the suspension at all. I have them on my camaro...I can't tell the difference between the rubber ones and the solid aluminum.

EDIT:
The main reason for using the solid bushings would be for a subframed car to eliminate some flexing between the subframe and the rear frame rails combined with a set of subframe connectors. Full framed cars may not see any real advantages over the stock rubber body mounts.

[wmhjr]

Rubber does soften the ride a little over poly, and poly is not as harsh as solid. Been there. Remember that to the driver/passenger - EVERYTHING between you and the road is part of the suspension. Heck, you can feel the difference when you reinforce a chassis - why would you not feel the difference in changing bushins (when the thickness is pretty large as in this case). I noticed that solids seem to resonate road surface stuff more than rubber or poly.

The other thing solids do is to REALLY tie the body to the frame. This is a really good thing for a track car - forcing articulation more to where you want it. So the body becomes even more of a frame component. Not necessarily so good in a street car - where you might have some really nice gaps and lines? Depending on the car, it means that as the frame flexes (and they all do) the body will be forced through more articulation as it's tied hard to the frame. Think of those door jambs, etc.

I think it's all a matter of what you have and what you want. If you have a relatively mild suspension and switch to solids (full frame or unibody) I'd bet you're gonna feel them. If you have a full out performance suspension, your ride is probably already pretty hard and you may not notice the difference as much. If you have a real nicely done car, solids may result in paint chips and cracks in some areas. If your car is a track car, who cares?

[68Formula]

A few comments from my side:

Of all the times someone has said solid mounts will make the ride too harsh - they haven't actually used them.

After about 10 years of aging, how effective is/were the rubber mounts at damping, anyway?

If these are supposed to dampen the ride, they would have to do it in a range that is perceptible to the driver. This means they had to have been tuned from the factory (size, thickness, material properties) to work in a particular frequency range. Once you change the material (or it's properties degrade), you change the frequency range that it works in. Bottom line, if rubber was doing it's job, then poly isn't going to be any more of a damper than a solid mount.

As for a an improvement in handling... Even though we're talking a full-framed car, the chassis is still flexing quite a bit during load. If you've ever been in a full framed car before and after a rollbar install, you can definitely feel the difference. Attaching the body directly allows it to act as a stiffening member against torsion. More load energy will be transferred into springs and shocks (which are designed for damping). The car will feel more secure, and more predictable.

One final thought. I've often wondered if this would have happened, if they guy had on solid mounts.

http://blog.oregonlive.com/breakingnews/2007/07/two_in_critical_condition_afte.html

[wmhjr]

68formual, you're largely right. Except at least in this case I've got personal experience with them. So the statement that "Of all the times someone has said solid mounts will make the ride too harsh - they haven't actually used them" really isn't accurate. At least not for everyone.

You're abolutely right in that there is already flex in a full frame body AND frame. That's the point I was making if you have a real nice body and paint on your car with good gaps. First of all, I'm comparing NEW rubber with poly and with solid - not worn out rubber. Comparing worn out rubber to poly and solid is like comparing the performance of a 200k stock motor with 8.5 compression to a fresh motor with 11. Anyway, I absolutely agree that the solids may give you a slightly more solid feel because the body provides just a bit more structural integrity to allow the suspension to do its job. But in doing so the body will also flex a bit more than it does with rubber or poly bushings. That means if you've got tight clearances already, or some weld joints that really don't like too much flex, you increase your chances of paint chipping off in the door jambs, front clip, etc - and of cracks in your paint in those flex areas. Anybody who has ever built a convertible will know EXACTLY what I'm talking about since there is already so little support you can really see the differences. As for the ride I think it's pretty relative and really depends on the rest of the car.

As for whethter the accident would have happened with solid mounts, I think you're massively overstating the situation. JMHO. You could wonder if a Lee box would have prevented it. Or a larger sway bar. Or correct front geometry.

Or just good driving.

[68Formula]

First of all, I'm comparing NEW rubber with poly and with solid - not worn out rubber. Comparing worn out rubber to poly and solid is like comparing the performance of a 200k stock motor with 8.5 compression to a fresh motor with 11.

The point I was making with the worn out rubber is that someone replacing worn out rubber with solid is certainly not going to feel a difference. If your old bushings are cr@p and you replace them with solids, don't expect to feel a difference in ride. And secondly, new rubber eventually degrades, so how long would you see a benefit if it existed in the first place.



As for whethter the accident would have happened with solid mounts, I think you're massively overstating the situation. JMHO. You could wonder if a Lee box would have prevented it. Or a larger sway bar. Or correct front geometry.

Or just good driving.

My point here is not whether the accident would have taken place, but rather, would the body have separated from the frame. It's certainly conjecture since we don't know if the bushings were worn, or if the solids would have prevented the bolts from being loaded so much they either sheared or were torn out of the body threads. Perhaps the outcome would have been exactly the same, but I wanted people to be aware that that can, and has happened.

As for the body flexing and breaking welds... The body and frame being securely mounted complement each other. Both will have less flex and as I stated before more energy will transfer to the suspension instead.

[vintageracer]

I have used poly bushings in 10 plus 68-72 A body convertibles. I would ONLY use poly bushings or other "solid" type of bushing in a convertible. They make a convertible a MUCH more solid car and significantly reduce cowl shake since there are 4 body bushings right under the cowl. Convertibles ride better, drive better and "feel" much more solid with poly body mount bushings.

I also replaced all the body bushing in a 96 Impala SS I owned with the "police car" body bushings offered by GM for 9C1 Police Impala's. The police car bushings are poly. Once again a significant improvement in ride and made the car feel much more solid.

Poly body bushings or maybe I should say "solid" bushings get my vote in a coupe and especially a convertible.

[LateNight72]

@OP: All of my mounts that were made have all been equal height across the chassis. In the few sets I did make, I have not heard a complaint that they did not fit right, though that could have been from people just not letting me know. Either use fender washers to shim it, get new ones made or run poly.

I have my car on 1/2 height solids right now, and they are all the same height (3/8"). All my pickup points make good contact with the body.

Basically, unless you're running around the track 24/7, go with polyurethane.

Shep's right though. I no longer officially make them (though I will "prototype" them). Why? Because no one wants these things. People moan that they're car doesn't have the support of a '69 Camaro, but there's a reason.


One final thought. I've often wondered if this would have happened, if they guy had on solid mounts.

http://blog.oregonlive.com/breakingnews/2007/07/two_in_critical_condition_afte.html
Chances are it either would have stayed together, or more likely it would have pulled the bottom mount(s) through the frame.

[Addicted]

Well the new ones i pulled out (rubber) had 3 different sizes/ types. The regular or most predominate ones. One that is the same size but is more of a shock, it has no hole. Pretty sure there was two sets of those, one set above the rear wheels and one set in middle of frame rail under seats. The ones under the rear wheels are now floating and there is no anchor point in those, so just take it out or shim it up? The ones under the seat I dremeled the whole out a little as there was a nut there and the mount did not seat properly. The last size I believe is a smaller diameter but slightly taller...

I can't remember where i pulled that set from as i believe there is only one set though.

I cant see how all these could be the same size.

A little more info as I have not updated my build.(I little stuck here..) Front Suspension will be Spc springs, uppers and lowers arms, varishock, Afx spindles and arms. Rear currie 9 w/arms, watts link, spc springs, varishocks, hellwing bar. 525 BBC w/ 5 or 6 speed. Mostly street with a little solom corses and time trials.


Any suggestions here as if I have to go to poly what brand ? I heard the new energy stuff is squeaky?!

Thanks

[Roadbuster]

Did you get the convertible kit or the one for the hardtop?
The convertible one has more mounts.

An option on a 68 pontiac like mine was a convertible frame under the coupe body. It was called the heavy duty frame option and cost all of $15 in 1968. Unfortunately mine did not come with that option but it will have it now! :). There are two additional mounts (with bolts) under the cowl for a total of 4 there. I believe there are two more on the back of the frame. If you are doing a frame off go with the convertible mounts, and bolt them all in, modifying the body if required.

BTW the kits are different for a Chevy, Pontiac, Buick or Olds. The frames interchange but the mounts are slightly different.

[The WidowMaker]

my urethane mounts had a few different sizes as well. i cut 3/8 out of each bushing, so i still have a few different sizes.

the ones under my seats have a caged nut, but arent supposed to be bolted according to my directions. i plan to bolt them anyways.

also, i went from original rubber to a different set of urethane before the rebuild. i noticed ALOT more NVH. car didnt have much for interior or dynamat though.

[wmhjr]

My point here is not whether the accident would have taken place, but rather, would the body have separated from the frame. It's certainly conjecture since we don't know if the bushings were worn, or if the solids would have prevented the bolts from being loaded so much they either sheared or were torn out of the body threads. Perhaps the outcome would have been exactly the same, but I wanted people to be aware that that can, and has happened.

As for the body flexing and breaking welds... The body and frame being securely mounted complement each other. Both will have less flex and as I stated before more energy will transfer to the suspension instead.

My only comment would be...

I have no idea if the body would have separated with solids. Maybe it would have sheared the body mounts quicker. Maybe the body mounts are what broke. I know that when I pulled the body off the frame on my last project, the bushings would have had nothing to do with the ease in which the body would have come off the frame due to the rusted mounts. Who knows? Again, I think using this as an example is WAY out there and without foundation. There are plenty of reasons for why to do rubber, poly or solid but I seriously doubt that the accident situation is one of the factors. JMHO.

As for body flexing, I just have to disagree - with experience of having observed it. Saying that solid mounts will result in less body flex is a bit of a flawed argument to me, but.... Certainly the frame may flex less and it will handle better. No argument there. We all have our opinions, right?

Maybe we can talk Frank or somebody into a practical test, eh? Take a 1st Gen A-body vert that's in progress. Install rubber bushings. Measure door and front clip gaps. Then lift different areas of the car and watch the gaps. Replace with poly and repeat, then replace with solid and repeat. My suspicion is that up to a certain point, the rubber bushings will show the least change in gaps. Then the poly bushings, and you'll see immediate changes in gaps as you lift corners of the car with solids. Just a guess.

[CHILI442]

I'm building my '66 442 with solid mounts. I'm using solid mounts everwhere with hardware, even in the places the factory used dummy mounts. This car will also get a full 12 pt. cage.

Anyway, I used three kits from Competition Engineering (each kit has 4 mounts and 2 for the radiator, so 3 kits gave me 12 useable mounts) for a Camaro subframe. The holes in the frame are a little smaller than the stepped portion of the CE solid mount. Your option is to turn the step on the mount down about 1/8" on a lathe, or open up the holes in your frame (Mother Nature already did this for me in a couple spots.)

http://www.summitracing.com/parts/CEE-3027/

https://static1.pt-content.com/images/pt/2010/08/53-1.jpg

[wmhjr]

Now when you add a cage, obviously solid mounts make the most sense. Of course, when you have a 12pt cage, you leave the realms of a typical "street car". I had to read your post a couple times as initially I thought you were putting the cage in the vert - in which case I was wondering how it was designed. Then I realized the hardtop is getting the cage. Doh!

[68Formula]

My only comment would be...

As for body flexing, I just have to disagree - with experience of having observed it. Saying that solid mounts will result in less body flex is a bit of a flawed argument to me, but.... Certainly the frame may flex less and it will handle better. No argument there. We all have our opinions, right?

Maybe we can talk Frank or somebody into a practical test, eh? Take a 1st Gen A-body vert that's in progress. Install rubber bushings. Measure door and front clip gaps. Then lift different areas of the car and watch the gaps. Replace with poly and repeat, then replace with solid and repeat. My suspicion is that up to a certain point, the rubber bushings will show the least change in gaps. Then the poly bushings, and you'll see immediate changes in gaps as you lift corners of the car with solids. Just a guess.

If the frame is flexing less, so is the body. Lifting the body in various areas is not a practical test since we are talking about driving dynamics. When you drive all the force inputs have to be based on the tires not various parts of the body, since they are not in contact with the road. Don't forget you have a suspension, and that is the key difference. If you wanted to do a test, it would require accelerometers at various locations to determine the amplitude and frequency inputs. As far as measuring gaps, the best idea would be to attach strain gages across various areas while running a dynamic chassis vibration system or actual road course. A static test is not adequate.

[wmhjr]

If the frame is flexing less, so is the body. Lifting the body in various areas is not a practical test since we are talking about driving dynamics. When you drive all the force inputs have to be based on the tires not various parts of the body, since they are not in contact with the road. Don't forget you have a suspension, and that is the key difference. If you wanted to do a test, it would require accelerometers at various locations to determine the amplitude and frequency inputs. As far as measuring gaps, the best idea would be to attach strain gages across various areas while running a dynamic chassis vibration system or actual road course. A static test is not adequate.

Wrong. If the frame is flexing less that does NOT mean the body is. With non-solid bushings the frame can flex to some degree without the body flexing at all. The bushings are flexible (to some extent) isolators that are designed explicitly to do this. That is their entire purpose. With solid bushings the body MUST flex as the frame does.

In other words, with non-solid bushings, the frame may deflect xxx mm with zero body deflection.

A static test would be fine to prove/disprove this. You think a pothole doesn't result in on section of the frame lifting/dropping suddenly? But OK, let's take it further. Jack up one TIRE. Not the frame.

Again, completely agree that solids will tighten everything up. That's not always what you might want. The proof is in the pudding, and I've had the pudding.

[68Formula]

In other words, with non-solid bushings, the frame may deflect xxx mm with zero body deflection.


Wrong. If it does anything, it dampens energy, but it will not allow any amount frame movement with zero body movement.



A static test would be fine to prove/disprove this. You think a pothole doesn't result in on section of the frame lifting/dropping suddenly? But OK, let's take it further. Jack up one TIRE. Not the frame.


Yes the frame twist. I don't get where you thought I claimed it wouldn't. Yes, you have to put the input through a tire, not to the frame directly. And still, this is not a statics problem, it's a dynamics problem.



Again, completely agree that solids will tighten everything up. That's not always what you might want. The proof is in the pudding, and I've had the pudding.

When I did my bushings, it was the only change I made at that time. No other components were swapped out. I actually drove the vehicle over potholes (roads by my house sucked), nearby traintracks, and did a few hard turns in a parking lot that morning. I then did the swap, and immediately took it out again. Not only was the ride not any harsher (actually it felt better), but I had a bunch less body lean, and the car felt more connected. I also noticed a lot less movement and shake at the window frame of my 'vert (I tend to rest my hand there when I'm cruising). That was at least 6 years ago, and no broken welds or paint falling off. All the gaps are the same as before. And no, I don't have a roll cage.

Anyways I'm done with this thread. Good luck y'all.

[Addicted]

Thanks for all the input. Still had some ????'s Not answered. Please state the type that you DO recommend. Namebrands.


I 've tried to find a link to a diagram showing the three sizes and there locations. If anyone could post it that would be most helpful.

[Addicted]

How about these PST Polygraphite® ????

[LateNight72]

How about these PST Polygraphite® ????

I've heard decent things for those, and Prothanes. I can't personally comment, however.

I doubt any of them will squeak, about the same likelihood of solids clunking.

[wmhjr]

Wrong. If it does anything, it dampens energy, but it will not allow any amount frame movement with zero body movement.



We'll just have to agree to disagree.

[The WidowMaker]

Wrong. If it does anything, it dampens energy, but it will not allow any amount frame movement with zero body movement.



i like horses, but we're going to have to keep beating this one. the frame on the a-body allows for the connection of body and suspension parts and thats it. in its stock state it does NOT contribute to the stiffness of the overall ride like commonly thought. ive had mine on a rotisserie, and with one side locked, the frame can be twisted a HUGE amount.

so lets now look at the body mounts; plain and simple, rubber deflects. if your fame is twisting and there is some give in the rubber mounts (which there is), it is entirely possible that the frame can move (albeit slight) without the body moving. this is especially true since there is a bushing on the top and bottom which allows the body to move in both directions. so, while twisting some will be compressing a slight bit, and some with be extending when the bottom bushing compresses.

a solid or urethane mount will have much less movement and therefore use the body more for rotational resistance on the frame. your gaps will move more.

just my .02.

[The WidowMaker]

oh and to the OP, i used prothane mounts both times. good product and i never had any squeaking since they shouldnt be moving. the suspension bushings were a different story.......

[Addicted]

What the new energy stuff or something different? That diagram with the sizes would be great, cause the N.E. stuff only has a different size under the front core support and I really wanna say these taller but smaller mounts were under the body somewhere else.


Ill be back with pics.

[L & H Kustoms]

How about these PST Polygraphite® ????


Used these on several cars and they work great.

[ed1le]

I have used poly bushings in 10 plus 68-72 A body convertibles. I would ONLY use poly bushings or other "solid" type of bushing in a convertible. They make a convertible a MUCH more solid car and significantly reduce cowl shake since there are 4 body bushings right under the cowl. Convertibles ride better, drive better and "feel" much more solid with poly body mount bushings.

Poly body bushings or maybe I should say "solid" bushings get my vote in a coupe and especially a convertible.

I've been debating on whether to install rubber or poly mounts in my 'lark mainly b/c with the poly, I'm thinking I may get more body twist as they are less likely to absorb frame movement vs. stock rubber mounts.