05slpGT

Just got off the phone with Steeda. I asked them about the UCA before i saw your post and they said that with the lowering springs from Steeda the pinion angle will be fine. I was told to rotate the driveshaft at 180, like many people have said, and if it isnt fixed, keep rotating it 90 degrees until the noise is gone. I guess im going to give it a shot this weekend and see if i have any luck

tdbrown75

I believe my vibration is fixed. During the gear install the mechanic noticed some casting left on the carrier where the ring gear seats. He says this would cause the ring not to lay perfectly flat against the carrier surface and could have produced the vibe. I took the car out on the highway and up to 90 MPH and it was smooth as butter.

The bad news is I had a small amount of whine on deceleration before, and now it’s about 30-40% louder and over a larger range. He’s going to tear back into it tomorrow to check the pattern and make adjustments to see if he can quiet it down.

I have an aftermarket adjustable panhard bar and UCA with firmer bushings so I don’t expect 100% silence. If he can just get it back where it was before I’ll be thrilled. Also the car felt plenty peppy with the 3.73s and the RPMs were MUCH better on the highway.

Sorry 05slpGT does not look like I’m going to help you get to the bottom of yours. Have you considered going back to the two-piece shaft as another possible thing to try? I have read the pinion angle needs to be adjusted with a one piece regardless of whether or not you lower.

Tim

moosestang

Wouldn't that have been there with the stock gears?

tdbrown75

Yes but probably over 110MPH or so which I hardly ever see. It's that or it was the gear install, or perhaps that non GT-500 pinion bearing. Who knows, but it's gone now at least at "cruising speeds".

Tim

tdbrown75

I just spoke to my installer. He stayed late last night to make some additional adjustments. He adjusted the pinion depth and reduced the backlash from .12 to .10 to silence the whine.

Tim

tdbrown75

05slpGT any luck with clocking your drive shaft?

808muscle

I rotated mine 180 degrees and even tried a second one piece DS. Adjusted the pinion angle dozens of times using a analog and digital angle finder. I could never get rid of all the vibrations. My car is an automatic and was not lowered. Plenty of threads where autos have a real issue with vibration so I coughed it up to that and gave up and went back to the stocker.

You should at least check it. You can pick up the angle finder at home depot for $12. Nice to know if your within the specs.