SapphireHawk

I have a very bad vibration in my drivetrain at any speeds above 15mph. I searched for other vibration threads and most where at certian speeds (usually high).

Recent Mods:
Strange 12 bolt
1350 yoke in Stock DS (pressed in with vice by me)
Spohn Adj. Torque Arm
Spohn Adj. LCAs and relocation brakets
Spohn Adj. Panhard rod

I know any of those things could probably cause the vibration, I have ordered a new DS from Billingsley which I hope may resolve the problem. Does anyone have any other suggestions, could it be my pinion angle? I set it to -1 using spohn's instructions which did not indicate the rear had to be a ride height (it wasn't).

bmfcamaro

iTrader: (1)

i have the same setup. i am installing my new ape chromoly driveshaft in 2 weeks. i will let you know.

SapphireHawk

TTT any ideas???

Tranzor

Just make sure everything is lined up nice and straight... my Moser was off just a bit and has been the cause of a major driveline vibration. It was barely noticeable with the stock driveshaft, mostly because I think it had a little give to it. I switched to Denny's Nitrous Ready, and the vibration increased a ton... mostly because it doesn't have any give in it at all, so it is less forgiving of stuff being out of alignment.

Had to put the car up on a rack, and straighten everything out... a big PITA. They say these aftermarket rears are direct bolt-ins, yeah right.

TRex

iTrader: (3)

Josh, have you tried it up on jackstands with the wheels off ? I know you didn't change the wheels, but it would reduce the load on the axles.

Also, you might remove diff and run it, that would allow only the ds and pinion to spin, taking the axle and diff out of the equation.

SapphireHawk

Now that you mentioned wheels, I just remebered that I found some wheel weights on the garage floor.

WS6HUMMER

iTrader: (19)

I recently installed a Moser 9", I have been trying find a vibration in the rear of my car also. I was wondering since my car is lowered and I know the rear is shifted 1/4" to the left if this may be the problem? I plan on getting an adj panhard bar anyway but just did'nt know if maybe this was contributing to the vibration.

Tranzor

if it is off, it can contribute to the vibration because that means your drivetrain isn't lined up properly... the adj. panhard should help fix that.

WS6HUMMER

iTrader: (19)

Glad to hear that, thanks.

jerflash

i have almost the same setup but with a moser 12 bolt and i have the panhard bar

i have everything as straight as i can get it; wheels are centered under the car notic that wh but ien toy senter the wheels the pinion yoke is still closer to the the passanger side which is odd

only vibration i have is on decel and its not that bad but the rear wines in decel

wrencher

iTrader: (2)

If it is a bad vibration & it gets worse undr accel it is likely the pinion angle.
You have the angle gauge right? Look at this:
http://www.rosslertrans.com/Tips/Pinion.htm
It has to be checked with the car level & rear axle at ride height.
Dont drive it with the angle off real far can cause problems.

SapphireHawk

It gets worse with speed too. The faster I am going even costing the more it vibrates.

wrencher

iTrader: (2)

Still sound like P/A could be the problem, re-check the angle.
If you have to run it at ride height in the air on jack stands & see if that helps chase it down.

bmfcamaro

iTrader: (1)

i have checked the pinion angle many times and set it at -2 and 0 it still vibrates. i am beginning to think its the torque arms. there are many of these issues with spohn torque arms out there. check on ls1 and ls2 and there are more. i have talked to spohn before and they said they have never heard of it. i brougt my car to a local drivetrain shop and he said that the shackle setup moves thus causing the angle to change. spohn said that the pinion angle doesnt change WTF. these torque arms are the craziest things. noone can figure them out. it seems like maybe there is a bad batch or jig and we have untrue ones or something. what can explain this. i cant go over 80 without feeling like my car will explode and under decel i get clunk clunk clunk and worse if i go over a defect in the road. it sounds like my drivetrain will fall off my car. i have double and triple checked all the bolts. my t/a bolts have never gotten loose. talk about driving you insane . i am at my wits end with this t/a. that shackle setup has to move. i wish i can get it on camera.

SapphireHawk

Yeah I am going to check it out tonight. Its kinda scary running a car up to 40+ mph on jackstands though.
Better make sure I back into the garage just in case.

Have you tried swaping in the stock T/A to see if it fixes the problem?

991LE

iTrader: (2)

I would vote for pinion angle.

Did you ding up the driveshaft when you installed the Ujoints?

SapphireHawk

I'm thinking it is either the pinion angle or the rear not being centered with the adjustable panhard rod.

The vice did dig into the DS pretty hard when I was installing the ujoint. Hopefully the Strange DS will be waiting at home.

991LE

iTrader: (2)

I measured a center point on the car up near the tranny crossmember. I measured from that center point to each side of the rear. I adjusted it until the measurements were the same. It wasn't off very much, but it was off a little.

bmfcamaro

iTrader: (1)

i broke my stock t/a after getting the moser rear, but there was vibration with the stock one for the short time it lasted. i also have an adj panhard i thought that that might fix it and it didnt help.

WS6HUMMER

iTrader: (19)

I think this may be my problem and also explain why I've had vibration with both rear ends. So you're saying the stock t/a bent or something causing the vibration? If so this would explain a lot for me. When I installed my Moser 9" recently I discovered that the t/a had hit the trans tunnel a few times. It actually messed up the bottom of the car a little. I checked trans and engine mounts and a few other things but nothings broken.