Black02SLPSS

iTrader: (5)

Ok i have been playing with the pinion angle on my car for awhile now. I have a UMI adjustable full length torque arm, im lowered with strano springs and i have poly motor mounts and transmission mount. the vibrations start happening at about 60ish and get progressivly worse the faster you go. But anything below 60 its perfectly smooth. When im going down the highway and i put it in neutral and the engine returns to idle its still vibrating. So i dont think its the poly trans mount thats causing it. Currently my pinion angle is -2 and the drive shaft angle is 1. So that would leave me with a -1 for a total angle right? Oh and i also have 4.10s if that makes any difference

LT1-DAN

Did you check the u-joints?

Elliott's94Z

iTrader: (12)

What about the driveshaft???

Black02SLPSS

iTrader: (5)

Ujoints were replaced not too long ago and the driveshaft was balanced at the time of the ujoints being replaced. Also there is no play in the rear but the front has a small amount of play in it, but i think that could be the output shaft bushing having a little play in it. However i had my dad get it up to 80mph while it was on jackstands and i got under it and put my hand on the rear end and it was vibrating and shaking pretty good and the transmission crossmember there was no vibration at all.

2tone

iTrader: (1)

I have the same problem! I just installed poly and energy s. tranny mounts. I have motive 3.42s but have no idea what pinion angle they are at. I will put it in nuetral later to see if it stops or not. Please post if you solve the problem. I will do the same. Thanks.

Black02SLPSS

iTrader: (5)

Im thinkin the guy that installed the gears did something wrong since it is localized right in the rear end. But who knows.

CranMaro99

iTrader: (10)

I have the same problem, and at the moment am all stock on suspension.

I doubt it is the actual rear end.

tc3

iTrader: (2)

bent axle shaft

Black02SLPSS

iTrader: (5)

how would you diagnose a bent axle shaft?

Black02SLPSS

iTrader: (5)

bumpity

getusumws6

iTrader: (9)

^ take it out

98trans-am

iTrader: (4)

how often are you at that speed? well assuming you dont travel at that speed daily have you thought about it maybe being a wheel balancing issue?

Black02SLPSS

iTrader: (5)

In reality im not at that speed too often. The speed limits out here are like 70-75 on the highways and 75-80 on the interstates. As far as the tires go they are brand new with maybe 1000 miles on them. Ill hafta take the axles out and check them one of these days. Also for those pinion angle gurus out there do i have mine set right? I have it set -2 at the rear end and +1 on the driveshaft so that would leave me with a -1 for the total angle?

Thanks