I have heard that trailing arms with polyurethane bushings on each end will cause suspension bind. Can anybody explain the physics of this to me? If it's true, I'll be having a set of Hotchkis trailing arms for sale soon.

 

I know of no particular problem with that on these particular cars. Some of the suspension companies that want to sell you something else will tell you that, then sell you an aluminum bushing that has even less flex than polyurethane... go figure...

I have the Lakewood rear control arms with poly bushings on my car, I have no bind problems that I'm aware of.

 

I personally have not use polyurethane bushings on my f-body, but I can explain why they might bind, and I have heard from lots of people in the autocross community that say they do bind.
During cornering you rear axle will lift on one side and lower on the other. If you could look at your car during a corner manuver it would look as if your axle is rotating about the differential. In order for this to happen the LCA have to move up and down as well as rotate. Since your mount to the axle and the car are solid and do not move the lower control arm must give to complete the motion. Rubber bushings allow for the bolts to somewhat rotate in the LCA, but harder polyurethane bushings do not. The polys are great for drag racing, since the axle must only move in one plane to get a good launch. 1LE bushings are a good comprimise and if you are good inspecting your car everyso often to make sure everything is tight LCA's with poly and a spherical rod end are a good solution. The rod end will allow for the rotation of the mounts and in doing so provide the freedom of movement the axle needs with the least amount of resistance.