Need to put some thought into a third link/torque arm since I shit canned my torque tube. There is no way I can run equal length with the wishbones so I need something that will have some movement. Give me some photo Ideas.
I have split my bones and have limited space to run a long link. Thinking I can run an arm to the rusty crossmember I have sitting in place.
Most hot rods have limited suspension travel, but the bigger the difference in the length of the wishbones and torque arm(S) will cause the rear end to rotate (pinion up and down) and bind due to the different arcs of the arms.
^^^^^^Only if torque arm is mounted to frame^^^^^^^^^^^^^^^^^^ In post 3 it's just along for the ride making trailing arms a little more stronger.......................................
So with my wish bones split to the outside of the frame and the car has a short wheel base and the fact that I will be straddling the drive shaft there is no way the torque arm can be long. There has to be some sort of a setup. On my T modified I built a bracket on the wishbone that goes up to the top bolt on the backing plate so the rear can not rotate. I guess I might have to go that route again.
Your wishbones mount solidly to your axle (not to a pivoting joint). Any other rod should only go between the axle and the radius rods. Don’t attach it to the frame. Sent from my iPhone using The H.A.M.B. mobile app
I realise how HRW does their system, but their system is designed to be a fit this yourself at home deal with little fabrication required. I must say though their open drive conversion system is stellar as are their crown wheel and pinion conversions for slide in axles we have done 3 now. 8 But Down under we need a seperate attachment point (generally for compliance) so the bones are split enough to clear the drive shaft and a 3 pivot point set up is used( well thats how we did it on a model A) using 3/4" tie rod ends and they all are equal length so pivot like a torque tube. To my way of thinking this is a much stronger way of doing it with 3 attachment points. Our torque arm is something like Schedule 60 heavy wall tube. The bend in it is to keep the floor flat under the seat base with a gusset for strength as My sons car has an 8" step in the rear. It may not be the best design but as all do ,this evolved. The goofy step on the rear axle end is to clear the u joint. Believe me you do need a torque arm as the one in out 32 had the nut on the 3/4 tie rod end come loose and every time you backed off the gas it or got on it the arm would go bang bang . Put a rattle gun on it 10hrs from home problem
I like your set up. Being my car is a wanna be ole school looking race car I could build a top link on the wish bones and it would look good. I do like your set up being that it is hidden.
I've seen threads along this line before. With the set up just as it is now, I don't see any need for a third link. I understand that ideally, the wishbones form a triangle and that should keep the rear end square in the car, better than the trapezoid created when they are split. But, in my mind splitting the wishbones doesn't cause the need for a third link. What makes that necessary is doing away with the torque tube, if and only if, the wishbones are not up to the task of keeping the axle housing from rotating. The general consensus seems to be that the '36 bones are too weak to do that, but the '40 style are beefier. Beefy enough? I don't know. I'm not trying to be a wise guy, I just wonder how many of these mods are done because, in theory, you need to compensate for the removal of the torque tube. It may be that there is enough built in over engineering to allow for safe operation without an additional link. And, doesn't the need depend on the torque applied and traction available? Rusty Rocket, Love the car!!!!
It needs something. I broke the bones on my T modified(didnt even think about axle wrap when I built it) I have come up with a solution though.
A guy I know down on the coast here has a 32 chev sedan with 4 wishbones locating the rear. All bolted to backing plate bolts. It looks great under his car but may be too bulky for your little rig.
Can I ask if these were the lighter '36 bones or the later heavier ones? And where did they break? Again, not arguing, just trying to learn.
I've seen them bend, kink and welds separate under flathead power with slicks. 40s style. About half way down.
My quick change rear has too much weight to the rear which caused mine to twist like a pretzel so I had the third link and new set of Wishbone so hopefully this will take care of the problem the quick-change is very heavy with an open drive shaft
I mounted a set of 36 bones on a 32 with a 383 SBC. If you mount them low, the stresses are much lower. They have been in service for ten years or so. No bends and no problems. No extra torque arms. The low mounting produces more of a push load and less of a bending load. I actually prefer to use a different design. I use a link on the left side that is free to rotate on both ends and a ladder bar on the right side. There is no binding and you always get equal traction. I have used this design since 64 on everything I have built except the stocker 32.
I have my Dad's '39 Ford - has open drive shaft w 327 chevy and 4 speed to a Columbia 2 speed rear end. We used early 1960's Chevy pick up truck trailing arms. They are a little bulky - but very strong. Done the job for almost 50 years.
Instead of a torque arm this is the route I'm going. This is my left over piece from splitting the bones.
That looks like a good solution. You might consider reinforcing the welded joints between the radius rod tubing and the forged ends. I've also put small fish plates over the joints in the inside where it's not readily visible.
I actually cut the forged end off the skinny part of the wishbone and moved it to the fatter end so everything tapers forward. So it will get a good weld on it.
There is numerous threads on here regarding torque arms and failing of radius rods without a torque arm. Just not a lot of pictures.
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