2000NemeSS

iTrader: (2)

Hi all,

Cant seem to find this vibration. I need answers on what else could be.

Symptom:
Vibration (feels like out of balance tire, consistant vibration, no grinding, no noise) can feel predominantly at 53mph and up. Can be felt in seats, console, and shifter.

Whats been checked:
3 sets of wheels and tires (currently Race Stars with 275/50-15 Nitto DR)
rechecked balance
Trans mount good
Torque Arm tight (aftermarket BMR TA, Non adustable) (Cars not Lowered)
U-joints have no play/not binding
no weights flung from driveshaft
stock rear with 99k (has superior axles, T-A girdle)
new shocks (nuts tight)
spohn LCAs with relocation brackets (bolts tight)
(may be forgetting something but that seems to be it)

Car History/condition:
LS1 car, 6 speed, 99k miles, has some play in the backlash between pinion and gear, had cover off when doing girdle, didnt notice anything out of ordinary, small amount of play up and down in axle bearings, cars seen the track a few times but never a clutch dump on the drag radials, vibration seems worst today then has been, had it up on lift few days ago, turned driveshaft 180* and seemed to help, had it up on lift today to check a few things out, once again it seems same if not worst as it did before turning driveshaft 180. I have an Eaton Posi unit and motive 4.10s going in on June 8th.

I really need some help hear, i am mechanically literate as I work at a dealer, but this one has got me puzzled, this type of vibration is normally like a tire but as you can tell I havent caught the problem yet.

z28bryan

iTrader: (7)

I have an old wheel that will not balance itself correctly in my street tire set. When I swap over to my race tire set, the vibration goes away. If you try two sets and have the vibration still, then you can eliminate it being due to a tire.

I've heard of some people adjusting their pinion angle and fixing their vibration.

2000NemeSS

iTrader: (2)

Thanks for chiming in, Ive been through 3 sets of wheels all having different tires, The cars ride height has not changed since Ive owned it, first mods I did to the car was Torque arm and lower control arms, I havent modded the suspension in over two years, considering the pinion angle hasnt changed and the vibration started within the last 5 months, why would pinion angle be an issue now?

2000NemeSS

iTrader: (2)

Put it up in the air and put it in gear, the right side is worst then the left, you can see the wheel wobbling, do believe I have a bent axle. You can feel the vibration up in the air without the wheels touching the ground.

Is it easy to bend an axle? I guess Superior isnt superior