Found a little bit of time to work on my setup. I'm planning on going after a very OEM solution.
After doing some measuring and hand calcs, I'd like to use Delrin (self-lubricating, high duro, high impact resistant, readily available) with a machined outer housing, same geometry on the inner compression limiter, and pressed into the same OEM forged track bar. Once installed, you'd never know the difference other than hopefully tighter steering.
I started by measuring everything, and copying that geometry into a CAD model.
Then I pressed out the bushings (they were SNUG), and sand blasted the rust off and measured some more. Looks like these were forged, then machined with a slight chamfer for the bushings.
I decided to cross section one of the bushings for measurements on material durometer and curiosity. Turns out they use natural rubber with an over molded mild steel piece to achieve the stiffness they’re looking for. The two biggest advantages here, for OEM are 1) Natural Rubber does not fatigue through use. That’s why it’s still used in all tires instead of purely synthetic solutions, the downside is it’s really soft so you need to do fancy stuff to hit your stiffness and displacement targets 2) Overmolding allows OEMs to not worry about contaminates. My biggest issue will be contaminates and plastic degradation based on that. Some use poly bushings with zert fittings, to grease, but Delrin doesn’t like grease (changes its properties a bit) and if you don’t keep up on the grease, it’ll do the opposite and just hold dirt in there.
I then modeled everything as OEM to have a baseline. I could probably supply .stp files if anyone needed them.
Them I engineered a new setup. This uses a machined outer housing that has a positive stop (so it’ll self-center when I press it in), and a thick side to aid in pressing it in without deformation. I’m using the same five thousandths interference as OEM. I might have to take a little more off since this will be more rigid than the OEM stamped one, but I’ll deal with than when I get there.
The Delrin center section has a shoulder on one side to help it from walking, and to make sure it’s centered when fully pressed in. This will have a decent amount of preload/interference to help combat the contaminates. I’m going to start at .25” wall thickness and 0.01” interference and see if I can press it in. I might have to take a little more off. Planning on 0.005” interference on both sides (ID and OD).
For the compression limiter/inner section, I’m going to copy the OEM geometry. I haven’t had any issues with that deflecting when torqueing the joint or walking during road events. Why change what works?
I’m really hoping this setup initially feels much better, doesn’t transmit much more noise/vibration, and lasts almost as long as the OEM ones do.
Next steps are finding time to machine two outer housings. The Delrin and compression limiter should be easy, pressing everything together should be easy, and install should be easy.