Red Bull 1968 Charger AWD Hemi 6 speed

[Bryce]

Good news about the shoulder bolts. HAHA. I will split the commission check with you.



I would through some washers under the head of the bolt. Also I would check the compressive strength of those bushings.

[Motorcitydak]

With the steering rack currently up in the air, I decided to work on the rear end a little more today. I am going to use a Watt's link to control the lateral movement of the rear axle and because its me, i am going to build it all myself. For the rear axle, I have one of Moser's circle track rear's. Its a ford 9 inch housing with Moser's full floater ends on it. I had it spec'd out a year or so ago. It has been sitting idly by while I messed around with the front end. I already have a 3 link built for it but no shock setup currently. I started off by putting the axle back into where it belongs



This shot is at ride height, which is 2.5 inches off the stock bumpstops



After that I started making my bell crank. I decided to build it with bolt holes 6 inches apart. I used some bronze bushings I had and will get another shoulder bolt that is the right length for this. You hear that Bryce?



Its made from the same stuff I used for the rockers in the front end. 3/8 thick 1.5 wide 6061 and a piece of 3/4x1 6061 in the middle I also drilled and tapped each side for 2 3/8 bolts. I am going to find some cap screws that I can counter sink into the 6061 for a flush fit since they interfere with the brackets as they sit



I marked and cleaned off the site where my bracket will be going. I decided on using an axle mounted bell crank to save overall weight. This will only add around 10# of unsprung weight vs around 30# if I used a Fays2 or something similar. I was very concerned about the clearance with the Moser fill cap. I assumed that I would have to remove and relocate it



This is the bracket that I made to attach to the axle. Its 1/2x1 steel bar with a piece of 1/8 plate welded to the front. The 1/2 has 3 3/8 holes tapped into it and I drilled 3 1/2 inch holes into the 1/8 to hold the shoulder bolt



I tacked that piece with the axle in place



Then pulled the axle out to finish up the process. I welded it to the housing and braced that with 1/8 plate





and was happy to see that with the bell crank in place, I still had good clearance with the fill cap



I was checking the spread of the 3 holes with 3 shoulder bolts, unfortunately the top hole for some reason decided to destroy that bolt. The bracket was still warm to the touch but I am not sure why this happened, but I blame Bryce. It was very hard to get this thing out



You can see that it messed up the top hole



I was able to drill the hole back out and chase the threads with the tap. The threads are fine. Im happy that I ordered 4 shoulder bolts tho

Here is the semi-finsihed product of my labors







You can see the second 1/8 plate with the 3 holes in there. I will make this setup double shear for strength

[Bryce]

Thanks for mentioning me, HAHA.

Looking good. FYI my chassi mounted watts link weighs 8.4 pounds.

Definetly do a double shear on a 1/2" bolt. There will be around 2000pounds of load on the pivot bolt. Shearing the bolt is not an issue its the bending moment on the bolt and the plate welded to the housing.

[Motorcitydak]

Wow, thats a super light weight frame for your Watt's. Yeah, I am for sure going to finish up that bracket. I want to get the frame brackets going rite now while the axle is back in. I can pull the axle again and finish up the bracket later

Any insight onto why that bolt got jacked like it did? I had bolts in those holes before I welded that piece to the axle and it was all fine. Then I was threading them in again. The other 2 went in just fine. I was putting that one in, it got really hard to turn then just about froze. I had to use a big pipe wrench to get it out and you can see the results

[Bryce]

It seems like the threads warped a little during the welding process. I would suggest alwasy re tapping the holes if possible. Also always use ani-seize for lubrication.

[kainedogg]

Awesome project man. Can't wait to see the finished product. I have been a huge fan of that Charger body style since the movie Bullet.

[Motorcitydak]

Thanks a lot. I love that scene in Bullit...rite until the Charger wrecked hard core. I am not quite at the finished product but I got a little closer today. I worked more on the Watt's link, making the frame brackets and figuring out the length of the links which I have ordered.

These are the brackets I made, just simple stuff. 1x2 1/8 wall box steel. Perfect since it has a 3/4 inside and my frame rails are just over 2 inches wide



Then after measuring for a while, I hacked some holes into the frame rails





Then tacked those brackets into place. I want to get my links just to make sure the angles are perfect. I set them at 80 degrees and used a 3/4 wood dowel to set this thing up



Does not seem like much I guess. I feel like I was out there for a long time with not much to show...o well. Ill get more stuff done later and hope to some day actually get a steering rack for it

[wellis77]

Sure beats my progress these days... Is there a pick-a-part or salvage yard near you that you can go measure some late model racks?

[Motorcitydak]

There is a pick-a-part I can walk around in but they will not have anything new enough to interest me there. The more I think about it, the more I think that any OEM rack is not going to be what I want. I just feel like a Woodward one is the only way to go

[Motorcitydak]

Just got these! Polished ZO6 calipers! For reference, they are sitting on 13 inch steel wheels

[wellis77]

nice score!!!

[Wesley J]

Its hard to tell dimensions from the pic but I wanted to mention something to look at. It looks like you're running a 3 link, correct? I'm wondering how long your upper link is and if you have a good feel for how much pinion angle change you're going to see during full suspension travel. The reason I say this is you could potentially have your rod ends binding in the swing shackle or whatever you call the aluminum pivot thingy. Not saying you will, just saying it's something to look at. Increasing the thickness of the center piece of Al or finding thinner rod ends would solve the problem in the case you had one.

And Bryce is correct, I'd mount that center pivot bolt in double shear as it'll see massive forces. To add to what Bryce said, that bolt could see much higher dynamic loads than 2000 lbs.

Cheers,

Wes

[ATOMonkey]

I wouldn't be worried about shear, either double or single on the bolt, as it's probably a 60ksi minimum.

I would be more worried about LCF fatigue from bending at the shoulder if an insufficient amount of clamp is maintained.

Neither are really a huge concern, as watts link is fairly common and people aren't dropping differentials out of their cars all the time.

[Bryce]

Shear is not the failure mode. Its going to be the bending and or deflection under load. Impulse loads are much higher than constant loads.

My 3-link has a watts and I have no rodend bind during suspension travel, ~10" UCA and ~22" LCA

[Motorcitydak]

I do not remember the length of my upper but I do know that it is very short, had to be for packaging purposes since I did not want to commit to intruding on passenger compartment space. I can change it down the road if its necessary. The rod ends iirc have 18 degrees of misalignment between the body and the ball if the ball is mounted rite to flat instead of being used with high misalignment spacers. I will have them tomorrow and will put them in this weekend to confirm everything is good.

I did draw out the rear suspension and mapped out the change of pinion angle during suspension travel. I do not remember what the degrees of change I would see but I do remember that it was minimal and I think it was more than acceptable.

Weather or not the shoulder bolt will stand up in single shear is debatable (sort of). I just do not want to worry about it tho so I am for sure doing double. That will put my mind at ease and keep it strong

Since I am not able to get a lock nut of anything on that bolt, when I put it in for good I am going to put some lock tite on it to keep the bolt from moving.

I did look around online for a while at Watt's link failure. I found a pic of one mustang that broke a single shear bolt. I doubt that it was a shoulder bolt and I do not know the grade of the failed bolt but again, I will not take the chance and will not have to worry about it

[Motorcitydak]

Spent a little time in there with a grinder. I could not stay very long tho just because of all the dust it put into the air. I guess its from all the old undercoating and dirt but I had to throw in the towel when my nose was running like crazy and it was all black...lol

Here is a bunch of junk I cut outta the back end. This pile includes the remnants of the trunk floor, the fuel tank crossmember, the shock crossmember and some flanges from the frame rail



Here is my now cleaner back end, way easier to get to all the junk thats still in there. This shot shows the links in the Watt's. I just got a digital angle finder which is nice. I bought it specifically to measure this, the bad news is that the arms are about 1.5 degrees off. I could not tell that with my other, swinging angle finder. Not a big deal tho, thats why I just tacked in the brackets. Im going to cut one back out and move it



and this is the rear end at ride height. The tires will sit about 3/8 further out because I do not have the drive plates on the full floater ends



Here is the purpose for making the room on the back end. I sort of have to do a push rod setup there and I sort of am doing it just because I can. Same deal as the front, 6 inches of allowed wheel travel using a 6.9 travel shock. I laid it out in card board in the house after I got smoked outta the garage

Ride height, the link end is slightly up because its angle got too bad at full droop



Full droop



and compression. The piece of the right is where the shocks will mount. With the car at ride height, the loads from the 2 coil overs will point rite at each other in the same piece of aluminum. That means that the chassis will really not see any of the load from having to support itself. I dunno about you but I think that is pretty cool



Thats all for now, I have to order the 6061 to build this thing and get more shoulder bolts and bushings (for Bryce)

[Motorcitydak]

Bryce, about those bushings I have in the steering setup. They are just there for spacers rite now, I got some 6061 tubing with .75 ID and walls of .25 and .375 I am just not sure which size I will be using yet. I may be picking up a mill so I can make just about anything if I get that

I messed around a little more but will be gone the next few weeks so no more progress for a little while. I have been concentrating on the rear end rite now. I finished up the watt's link and started work on the rear pushrod setup

For the Watt's, it was always going to be double shear. I like to think about things like this for at least a week to make sure that I like the design of the thing I am building. After figuring out what I liked, I built this. Its sort of a football shaped thing that spaced another piece of 1/8 to nicely support my shoulder bolt for the Watt's



Also I ordered this self locking shoulder bolt for the Watt's. It has a plastic pellet in the threads to lock it into place. Should work out nicely



Here is the football in place, the middle shoulder bolt is just longer than the others. I wanted them there to keep the piece in place during welding



Braced up with more 1/8 plate. Im happy with the way this turned out and do not think I will have any problems from this. I did realize that the upper bolt on the Watt's pivot will interfere with the oil filler of the axle. I am going to solve that by building a new rear plate for the pivot and threading the two bolts that hold the links then just trim the part that sticks out. I cannot get a bolt in the pivot with it mounted to the axle



Here is what I started making for the rear pushrod setup. Its all 3/8 6061. Unfortunately one piece of the 3 inch was backordered so I did not get it while I was building this. That would form the other horizontal plate. I have it now but no time to work on it. I also cut the flanges off my frame rail where this mounts to and plated over the top of it welding that directly to the vertical wall of the frame. I was going to weld in a vertical plate to the frame rail to connect the two sides but there is already one there from the factory because of the location of the stock bump stop, thanks Dodge!



Here it is sitting in place. It just barely fits between the stock wheel wells but it does fit and allow full motion of the rockers. You can also see the holes in the floor where the pushrods will pass thru to the axle. I will use a shock boot to seal this area up later. Something I like about this is just how far out I can put the mount for the spring on the axle housing and not have to modify the frame at all for the coil overs. It also saves a ton of room for a sway bar and exhaust by having the shocks up in the trunk. Does it matter if I mount the pushrod to the top of the axle shaft? or I can mount it to the lower control arm brackets which I built them to be able to easily hold a mount for that



Closer shot of the passenger side. I hope to wrap this up the next time I get some time in the garage



Sorry for the horrible pictures. Im not one who cares much about that but I know these are pretty bad yet I appreciate that most other build threads have way nicer pics

[wellis77]

looking good Steve!

[Motorcitydak]

Almost finished up the rear pushrod setup. I still need to make the 1/8 steel brackets to weld to the frame but I got this finished up so I can get the length of the pushrods. I got that and have ordered them, should be in in a few days so I can both those up and make the axle side brackets. After that the rear end is pretty much done. This is built very similar to the front end I did except the aluminum is 3/8 thick bolted together with 3/8 grade 8 bolts and I cut up 0.75 0.120 wall aluminum tubing for spacers. I am still waiting on my steering rack from Woodward, hoping that shows up some time soon.

Here is the finished pushrod frame sitting in place. I used some 1x1 aluminum as mock up shocks

[wellis77]

Looking good Steve.