9'' Frustration
9'' Frustration Well if been messing around with this moser 9'' the last few days got the longer driveshaft some vibration was still there so I figured it was pinion angle well I have the pinion angle around -2 on the angle finder ( I have the magnetic angle finder face facing the passenger side wheel) and it still vibrates mainly above 70. I have barely drivin the car and noticed the pinion seal seeping already the exhaust hits the pinion yoke I moved the rear away a little bit with the adjustable phb but it still hits. Im going to mess around with it a little bit more tommarow and if I cant get it maybe ill take it to a drivetrain specialist. Im really aggravated because this 9'' setup cost me some cash and now its probably gonna cost me more if I have to take it to a place to get it all setup. My car was fine before this swap no vibrations everything cleared fine now it just well seem all screwed. Any insight would be appreciated.
From BMR's website regarding setting the pinion angle.
"Setting Pinion Angle
Support vehicle under rear axle to load the suspension for pinion angle adjustment. Once suspension is loaded, attach the provided angle finder on the bottom of the rear end torque arm mounting plate and record the reading. Now place the angle finder on the driveshaft and record the reading. Subtract one angle from the other, this is your pinion angle. This angle is considered negative when the pinion points downward. It is best to start with 0 degrees pinion angle and adjust accordingly based on the cars launch characteristics and parts combination. As a rule of thumb, most automatics typically respond best to a -1 to -2 degree pinion angle while manual equipped cars respond best to a -2 to -3 degree pinion angle."
Your vibration is more than likely from the pinion angle being off, I'd adjust it again per the above instructions. Bob
"Setting Pinion Angle
Support vehicle under rear axle to load the suspension for pinion angle adjustment. Once suspension is loaded, attach the provided angle finder on the bottom of the rear end torque arm mounting plate and record the reading. Now place the angle finder on the driveshaft and record the reading. Subtract one angle from the other, this is your pinion angle. This angle is considered negative when the pinion points downward. It is best to start with 0 degrees pinion angle and adjust accordingly based on the cars launch characteristics and parts combination. As a rule of thumb, most automatics typically respond best to a -1 to -2 degree pinion angle while manual equipped cars respond best to a -2 to -3 degree pinion angle."
Your vibration is more than likely from the pinion angle being off, I'd adjust it again per the above instructions. Bob
Many of us have found that you need to get your pinion angle close to zero to stop vibration. And it has to be pretty damn close.
No offense to Bob or BMR, but I don't like that method (although it usually is close enough unless the geometry has changed). I prefer to take the driveshaft off. Then go up to the front of the car and measure the face of the crank pulley (vertical surface). Go to your pinion yoke (vertical surface) and adjust the pinion yoke until the angle matches the crank pulley. That puts you at zero. If you want to run negative pinion, just adjust the TA to move the pinion downward as much as you want at that point.
After you drive it, re-check the angle. Also, if you've driven very far with the angle way off, you might need a new rear u-joint. It doesn't take long to ruin them if your angle is off by more than 3 degrees.
No offense to Bob or BMR, but I don't like that method (although it usually is close enough unless the geometry has changed). I prefer to take the driveshaft off. Then go up to the front of the car and measure the face of the crank pulley (vertical surface). Go to your pinion yoke (vertical surface) and adjust the pinion yoke until the angle matches the crank pulley. That puts you at zero. If you want to run negative pinion, just adjust the TA to move the pinion downward as much as you want at that point.
After you drive it, re-check the angle. Also, if you've driven very far with the angle way off, you might need a new rear u-joint. It doesn't take long to ruin them if your angle is off by more than 3 degrees.
Many of us have found that you need to get your pinion angle close to zero to stop vibration. And it has to be pretty damn close.
No offense to Bob or BMR, but I don't like that method (although it usually is close enough unless the geometry has changed). I prefer to take the driveshaft off. Then go up to the front of the car and measure the face of the crank pulley (vertical surface). Go to your pinion yoke (vertical surface) and adjust the pinion yoke until the angle matches the crank pulley. That puts you at zero. If you want to run negative pinion, just adjust the TA to move the pinion downward as much as you want at that point.
After you drive it, re-check the angle. Also, if you've driven very far with the angle way off, you might need a new rear u-joint. It doesn't take long to ruin them if your angle is off by more than 3 degrees.
No offense to Bob or BMR, but I don't like that method (although it usually is close enough unless the geometry has changed). I prefer to take the driveshaft off. Then go up to the front of the car and measure the face of the crank pulley (vertical surface). Go to your pinion yoke (vertical surface) and adjust the pinion yoke until the angle matches the crank pulley. That puts you at zero. If you want to run negative pinion, just adjust the TA to move the pinion downward as much as you want at that point.
After you drive it, re-check the angle. Also, if you've driven very far with the angle way off, you might need a new rear u-joint. It doesn't take long to ruin them if your angle is off by more than 3 degrees.
Last edited by RamAir02TA77; Mar 13, 2009 at 10:18 PM.
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There is a driveline guy up in Danielsville, Performance Driveline. I heard he does good work and he owns a Ls1 z28 so he knows the cars.
On the vibration there is a bunch of things other than the driveshaft angle that could cause it. One the carrier itself being out of balance, I had that happen after installing a auburn carrier. Also sometimes you need to shim the transmission to get the proper angles. Also if you changed the mounts in anyway you may be feeling vibrations the factory bushing and mounts isolated. I know from the factory GM did ALOT to try and get the vibration out of driveline in these cars. If you look at the factory bushings and mounts they give ALOT. Another thing to try is change the driveshaft position 180 degrees from where it is now on the yoke. I've chased a few driveline vibrations and trust me its not quick or simple. My 88 GTA vibrated above 70 and we never could solve it. Kinda ruined the cars character, thats why GM really did their homework on the newer TAs and camaros. Too bad noone mentioned this possibility before you swaped it out. Another thing you will probably notice is ALOT more noise from the rear. Its normal but people hate it. These newer fbodies really transmit the noise into the body especially if the floor pan wasn't undercoated or rust proofed. That deadens alot of rear noise from getting in the car. Good luck
On the vibration there is a bunch of things other than the driveshaft angle that could cause it. One the carrier itself being out of balance, I had that happen after installing a auburn carrier. Also sometimes you need to shim the transmission to get the proper angles. Also if you changed the mounts in anyway you may be feeling vibrations the factory bushing and mounts isolated. I know from the factory GM did ALOT to try and get the vibration out of driveline in these cars. If you look at the factory bushings and mounts they give ALOT. Another thing to try is change the driveshaft position 180 degrees from where it is now on the yoke. I've chased a few driveline vibrations and trust me its not quick or simple. My 88 GTA vibrated above 70 and we never could solve it. Kinda ruined the cars character, thats why GM really did their homework on the newer TAs and camaros. Too bad noone mentioned this possibility before you swaped it out. Another thing you will probably notice is ALOT more noise from the rear. Its normal but people hate it. These newer fbodies really transmit the noise into the body especially if the floor pan wasn't undercoated or rust proofed. That deadens alot of rear noise from getting in the car. Good luck
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join the club! 1 simple fact: IF YOU BUY A MOSER 9" IT WILL LEAK!!!!!!!! my pinion seal went out within 2 weeks. moser uses cheap crappy seals. they have no quality control on their 9" kits.
P.S. don't waste your time calling moser because THEY DON'T CARE!
P.S. don't waste your time calling moser because THEY DON'T CARE!
Well thanks for the info guys I might end up taking it to performance driveline I also heard he does good work. It just sucks that I spend all this money for a "Bolt in" rearend and it vibrates well like a POS. And now im probably going to have to spend more money to have a drivetrain shop check it out. Everything is from jaws gear the center section jaws gear put together for me Jeff at jaws gear was helpful when I ordered all the stuff. The gear noise really wont bother me its not to noisy yet but this vibration is annoying. I should just sell all this stuff and put a 10 bolt back in lol the only thing I broke in a 10 bolt was the torsen got a little beat but I wanted a rearend that I didnt have to worry about breaking thus the 9''. I didnt change any mounts I just bolted in the 9'' and hello vibrations.
