I'm so relieved.

[GrayZ]

Originally Posted by rhipsher

I've had a vibration problem coming from the rear of my 90 Z for the past 1 1/2 or so and it's bugged the hell outta me as some of you already know. I've tried swapping the tires. No luck. I've replaced the rear wheel bearings. No luck. I've had a four point aligment done. No luck. Checked all of my bushings. Nothing loose. No luck. It's been bad enough that I couldn't even look out my rear view mirror because it shook so bad. I don't care how fast the car is it got to the point where it was no longer fun to drive anymore because above 60mph it felt unsafe. So I decided thats it I'm going to find and fix this problem if it kills me. I've taken this car to 179mph many times and now I can't even take it above 60mph? F that. And I found it and fixed it today damn it. It was my fault all along. A total rookie mistake that I can't believe I made. But it was something I had suspected all along. The last time I replaced my throwout bearing/fidanza and clutch disk I installed my drive shaft 180 degrees out. And let me tell you something! That makes all the difference in the world. When I spun the wheel by hand and watched the drive shaft I swear it looked like it had 1/8 in run out. When I rotated it 180 and bolted it back together and spun it by hand again it ran totally true. The shaft and the ujoint rear diff already had white paint on them to mark proper orientation and I swore I installed it right. I must have been in a rush. But it runs totally smooth now. No vibration or roaring noise. I felt like slapping myself over that one.

Glad to hear you found you're problem. I was wondering, What mods have you done to your car?? I'm assuming it's a 415 ?? Not to many of our Z's are able to leg out, much over 166, unless highly modded. Always good to compare notes.