can any one give some advice on bushing replacement,to use poly or the stock rubber,i've been told the poly makes the ride to stiff and will turn the car into a rattle box after 10'000 miles....72 cutlass convert.....thanxxxxxxxx

 

This a old thread too but worth discussing.

poly bushings will make the car stiffer... and stock rubber will give you back your stock softer ride.

poly pluses-
-stiff in turns and prevents body and suspension roll.
-handles torque better
-pretty much lasts forever
-cost is relatively cheap

poly minuses-
-transfer more of the shock of the road through the suspension

rubber pluses-
- soft factory ride
- for show they look stock
- keep down noise being transfered through the drive line

rubber minuses
- does not transfer torque as well as poly
- body sway more in turns
- has a much shorter life and breaks down with heat and oil etc.
- cost tends to be more than poly ??? yes that is correct. at least compared to moog.

I am sure there are more opinions...Jim

 

Poly on the rear control arms is a problem. The typical GM 4-link rear suspension causes the control arms to twist slightly as the suspension moves. The factory rubber bushings are soft enough that they absorb this twisting with no problem. Poly bushings are much harder and will cause the rear suspension to bind. The solution is to use the upper arms that have ball fittings at the forward end. This solves the binding problem.

 

I redid the suspension on my car a few years ago and I ordered rubber bushings. I am still pleased with the ride quality and lack of road noise in my car. The only thing I have to do now is restore the interior and I will be set.