Alrighty... this is going to take a while, but bear with me, I need some suggestions...

1st. I did a gear swap about 500 miles ago with Motive 4.10's. I've had it back the original shop 3x and the 1st time the adjusted the backlash of the gears, and made sure everything was ok. I've had a whine that is pretty crazy, but they've said it was normal, and typically this bad in '97 cars. They've done tons of these rears, and have not been able to get a single 1997 rearend quiet.

2nd. While the gear swap was being done I have my stock steel DS balanced... they did it on a low RPM machine, I took it back after have a VERY bad vibration at highway speeds (>55 mph), they then re-balanced it on a high rpm machine.

3rd. THe car sat all winter on bald Nitto DRs.

Ok... here's the deal. I've got a vibration at speeds >70 mph, I can feel it through the shifter/gas pedal/clutch pedal. I can sometimes feel a slight vibration at ~40 mph, but only at certian loading conditions.

What could be the cause of these problems? I'm racking my brain pretty bad, but don't have the $$ to replace everything again.

Here are my thought:
1. Gears are in wrong? Problem with that is no one I've known had gotten a vibration problem from a gear swap, right?
2. Driveshaft got FUBAR'd when they balanced it... I should get a Aluminum unit?
3. Tires are MAJORLY flattened and causing the vibration...


I NEED INPUT!!!!

 

I also have a vibration after 70mph. Can't figure it out either. It's not in the steering wheel either, it seems like it's coming from the back or under the car. Strange. I want an aluminum drivrshaft.

Mike

 

Put the rear up on jacks so you can run the car in the garage. Drive it up to 70mph and feel the vibration. Remove your rear wheels and do it again. If you still have vibrations, then it's not your wheels. Remove your driveshaft and do it again. If you still have vibrations it's not the rear end or the driveshaft. If it goes away, borrow someone else's driveshaft and try it again.

Etc....

Dave