I just yesterday replaced the strut rod bushings with polyurethane, replaced all brake pads, replaced rear rotors, and flushed brake fluid with new. Took a test drive when I was done and everything seemed good.

This morning when I got on the highway, I started to get significant wheel shudder in the steering wheel at about 55 to 60 MPH. Below that, there was no problem, but above and I was concerned enough to get off the highway and stay on the 45 MPH roads to work.

What is the likely problem? Is it with the control arm and the new poly bushings? I checked the front rotors for any warping and they were very straight. Thanks.

Chris
1995 945T

Chris,

I don't know whether this is the first time you have ever changed these bushings on this model car, but I had a similar experience the first time I ever changed mine. Did you preload the suspension before you torqued them?

I had a friend help and show me how to change them the first time and discovered later how critical it is that you torque them with the full weight on the suspension (preloaded). We were in a hurry, and I think I was supposed to check them later but never did. The vibration developed quickly and it did not go away until I properly torqued them.

By that time, however, it was too late. They were already damaged (rubber not poly) and I changed them for new Boge's. That was nearly 80k trouble free miles ago.

Oh, and one piece of unsolicited advice. Stay away from OEM rotors. The brembos hold up better and seem less inclined to warp.

Oh, and another. Always do whatever spook says....

Happy Motoring and Happy Fixing...

Mark
'93 940 240k Miles

I have the poly bushings on my '93 940. I think they may transmit more vibration to the steering wheel than the original rubber bushings. I can't be sure since I didn't drive a lot on the old bushings which were shot. I did put new tires on and had to get them balanced twice before the vibrations went to an acceptable level. There's quite a bit of road feel through those bushings.

Chris,

What is very straight? If you didn't use a dial indicator, you wasted your time. All rotors look straight. If you have more than .004" runout, you'll probably notice it.

If you checked runout with a dial indicator and you're ok, you might want to check the balance on the tires and trueness of the rims.

someguyfromMaryland

Dear Chris,

Good p.m. and may this find you well. Did you perchance check/clean/lube the caliper pins? The shudder might be produced by a brake pad dragging against the rotor, because the caliper is not retracting fully, owing to (a) dry/dirty/corroded caliper pin(s).

If this is the problem, it can be cured by applying a thin coating of synthetic (silicone) brake grease to each of the two pins, on which each caliper moves.

While I doubt you left anything loose, check that all front-end bolts are torqued to spec.

Hope this helps to get you rolling smoothly.

Yours faithfully,

spook