Well I installed A BMR TR and I still have a vibration at 80+ its a lot better than before but is still there. TA is set to –3, -2.

For those who didn’t see my other post here is some info.

New Moser 12 bolt
Shortened (˝”) and balanced Drive shaft.
Vibration starts at around 80 and gets worse
I can mostly feel it through the shifter. And I can also hear it.

any info??? this is getting old

 

TTT anyone???

 

t56 is notrious for vibrating. if you went to a lower gear its spinning faster making the vibration worse. you may want to pull the driveshaft and have them double check the balance. here only one shop balances the driveshaft over 70, so they may have balnced it at a lower speed not really helping out a low geard car.

when i was in school for this crap they told us to put hose calmps on the shaft and drive the car, keep turning the clamp until the vibration gets less thes add another until it runs smooth.

its a getto fix but i could tell you if its the shaft or not, and could be something to go by if that is the problem.

also, if you have a solid or poly mount it will greatly increas all road engine and driveline noise. even on my a4

 

I don’t think you understand this is not a little vibration at all. Its stats off kind of small but quickly grows and feels like the drive train is going to vibrate apart. Something is very wrong. I have had the drive shaft balanced twice at a shop that both a Chevy dealer around here and a local shop recommends. According to the DS guy it is as balanced is it could possibly be.

I do have another idea though.

I have the C clamp eliminators so the axels are held in by the bearings, which are held in by the brake brackets. Well I was thinking what if the bearings have a little movement in there causing the whole axel to move from left to right just a few fractions of an inch? The rear does make squeaking sounds while going around turns especial left ones. AND my right axel seal looks like it melted a little from heat. Also the center of the rear gets hot which i don't know it this is normal but it is only in the 40s here and i wouldn't think that it would get this hot now..

I was also told that drive shaft length could cause a vibration. i had mine cut by 1/2". I measured it myself so i could have messed up. I did this bc I herd if you don’t than your trans will get destroyed. What is the proper length of the DS? NO ONE seams to know which I also find hard to believe since all F- Body DS are the same length right??? I don’t think that each one is a custom length for each car but i could be wrong. If I am right about this than why the F*** doesn’t anyone know what the proper length for an F-Body with a Moser 12 bolt??????? Not even Moser: mad: and the only information i got from Moser was that their rears don’t Vibrate and it must be my DS or a Wheel that’s all they could tell me. I mean how many of these have been made and im the only one with this problem. But I’m not going to bash Moser just yet until I and sure that the rear itself is the problem. I know it could have easily have been something that I did. But no one seams to know what it is that I could have done wrong.. so again any help anyone who has installed one by themselves could help me solve my problem so please basically list everything your did while installing. Again I blew my 10 bolt but up until them I had NO vibration issues.

Here is a list of what I am working with again.

Rear
Moser 12 bolt
33 spline axels
Eastern posy
373 gears
1350 yoke
TA cover

DS
Cut by 1/2"
1350 installed
Balanced TWICE from a shop that everyone recommends

Tires rotated and vibration feels the same
BMR TA (trans mount type)
DS angel set to -3 using angel finder. I did this by putting angel finder on TA mount on the bottom of the rear and taking that angel ( 0 ) and subtracting the angel of the DS it self (3) = -3 car was supported by 2 jack stands positioned under the axel tubes. Is this right???
After market sway bar that goes under the rear

Problem:
I can feel the vibration at all speeds in all gears at all RPM clutch in or out but it really isn’t that noticeable till 75+ at which point it shakes mostly the shifter and eventually shakes the whole car it does feel like the DS but I am not sure. It also makes a wahhh wahhhh wahhhh noise AT 75+ only..
Left axel seal is leaking. It looks like it has folded or melted a little toward the back of the car.

I also have a McLeod Twin street that chatters like crazy sometimes. Which I think im going to remove as soon as I get the rear fixed BC I really don’t need such a clutch in till I really have some other mods and its not worth it right now.

EVERYTHING ELSE IN THE DRIVE TRAIN IS STOCK!!!!!! Again with no vibration problems before the Moser install!!! So please again give all your thoughts and ideas no mater what it is. If you think I have too much change in my cup holder and this is the problem please tell me.

Here is a link to LS1.com so you can see what they think overthere.
http://www.ls1.com/forums/index.html
Under LS1 drivetrain subject ***still vibrating***

Thanks again I don’t know what I would do without these boards J

 

Did you ever fix this? I've had nearly the same problem since just before you posted this and haven't found an answer yet. My vibration seems even worse then yours since mine starts at around 60mph and maybe even sooner then that but it's not that bad. I've also wondered myself about the bearing on axle setup but when I pull on a wheel with the car jacked up they seem to have no play. This vibration is driving me over the edge now.

 

I'm in a similar boat but mine is with the Moser 9in. Didn't have any vibes with the 10-bolts. After I got the 9in I've got bad vibe problems that start around 60mph and gets worse the higher you take it. I've been told by several folks that it's likely due to the DS being too short. I measured and it does seem a little short so I'll be ordering a Denny's shaft soon. I'm sick of this too so let's hope that does it. I trap 120+ so a car that won't go over 60 is no good to me.

 

new DS from Denny's fixed the problem for me. Smooth as butter @ 120+

 

yes i fixted the problem it was the DS