corvette1987coupe

I am trying to find replacement rubber, not ploy, bushings for the rear wheel spindle control rods. I have tried the dealer, NAPA, AutoZone, Carquest, etc. No one has the replacement rubber bushings. Only poly seem to be available. I am installing poly in the front, but would like to use rubber bushings in the rear. Any sources for these pieces?

steve40th

They dont make them. You either buy poly, delrin, or other hard plastic/rubbers or new dog bones.

BrianCunningham

I wouldn't use Delrin too hard, we have enough binding issues to deal with.

Use poly if you have to.

I bought rod ends, even better.

elkprairie

I replaced the "dog bones" bushings in my '84 with the poly ones this last winter and have been very satisfied with the ride. I had a sway when I let up on the gas with the old ones but that has gone away.

Radiostar929

does anyone have a squeaking issue with the poly spindle rods on a c4?

1984Z51auto

I did the rear of my 1984 with all poly bushings and a lot of their special grease years ago... after about 50K more miles and it is still quiet. It already rode rough (early Z51) so the bushings didn't seem to impact the ride.

MatthewMiller

I agree with this. Rod ends are the ideal solution except for NVH, but really they aren't even bad about that in the rear locations. But if you prefer rubber bushings (which I would understand), I'd look for new or "gently used" complete trailing and camber arms.

hcbph

Is the reason you don't want poly for ride, potential noise or what?
I wanted to improve handling on my 86 and got the full Banski rear suspension kit. No noise, improved tightness and handling on curved roads. It was worth it to me.

Just a thought.

MatthewMiller

It's not because of NVH. It's because the trailing arms and even the camber rods don't just move in a single plane around the pivot axes defined by the bolts. As the suspension moves up (into compression), the arc of the trailing arms means the upright moves backward and/or forward, and the arc of the camber rods means it moves outward and/or inward (depending on ride height and the angles of the links at static ride height). So the arms have move in multiple planes, but the axial bushings only allow one degree of freedom, which is around the bolts.

The giant and compliant factory rubber bushings have lots of "squish" to allow for that. And in fact, the rubber is bonded to the outer shell and inner sleeve anyway, so those bushings depend on the rubber compliance for all planes of movement. But the stiffer you make that bushing medium, the more resistance you create in any plane of movement other than around the bolt's axis. So urethane bushings actually have less resistance around the bolt axis, but considerably more resistance to movement off that axis. The end result is non-linear wheel rates, aka "bind." That's why you'll notice that nobody makes metal sleeves with Delrin bushings for the rear: they'd have so much bind that handling would really suffer, and you'd risk breaking something.

Rod ends, OTOH, allow fully free rotation on all planes, while constraining the pivot location precisely. They are the ideal solution, except of course for NVH characteristics and (sometimes) durability. So they are not the best solution if you want a smooth, quiet ride on the street. That said, I can't tell the difference between the NVH of the rod-end arms and the stock rubber bushings on my car. I'd think that the batwing bushings are the bigger factor in NVH for a C4 rear suspension. And durability of rod ends can be considerably improved by using the rubber boot covers offered by Banski, which keeps road grime out of the joints. And of course, if a rod end wears out it's trivially easy and pretty cheap to replace it.

All of this is why I recommend either factory rubber bushings or rod ends in the rear bushings, but not poly. Not that poly in the front control arms is not a problem because they really only move in one plane, around the pivot bolts.