Sorry to keep beating this horse but I'm still perplexed. After reading a few hundred threads about rearend vibration, the common link seems to be the 700R4 transmission and it seems to be the earlier cars. My car is an '84 has the 700R4, no positrac, drum brakes and steel driveshaft.

If you have ever fought the rearend vibration, please list what your car has for tranny, rearend, brakes and driveshaft. Maybe we can find some common ground here. Also please mention if you cured your vibration.

 

'88 GTA 305 TPI w/175,000 miles.

original 700r4 and rebuilt original 700r4 w/2000 Hughes lock up converter.

stock 3.27 9 bolt w/limited slip and Strange 3.42 12 bolt w/Eaton limited slip.

stock disc brakes and Baer disc brakes.

original stock steel 2.5", rebalanced original stock steel 2.5"w/new u-joints, untouched junkyard stock steel 2.5".

Not yet but hopefully within the next two weeks.

The only time the vibration has changed was when the driveshaft was removed and only a yoke was in the transmission. What do you know, no vibration. The only thing that has remained consistant in this has been a stock steel GM 2.5" driveshaft from an 82-92 F-body.

Rob

 

GM steel driveshafts on all F and G body cars have always been suspect. It also gets worse with age and mileage.

If they have miles on them, I send them out for new u-joints and have them balance it as well.

I lied, I throw the steel ones away and replace with aluminum where its possible lol

I still balance them.

I dont have vibration issues then.

This is assuming you have checked the tires/rims for being bent, good wheel/axle bearings, bent axles, etc.

later
Jeremy

 

Tires and wheels are not the problem. It does it without them on the car.

Bearings were replaced on the 9 bolt and the axles are good. The 12 bolt is new.

As I said earlier, the only thing that has remained constant has been a GM stock 2.5" steel driveshaft.

Soon that is going to be taken care of.

Rob

 

Check my reply in the other vibration thread.