Bad vibrations after installing adjsutable torque arm
11-20-2006, 10:25 PM
#1
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Bad vibrations after installing adjsutable torque arm First off I would like to verify we set the pinion angle correctly. When we were done the DS showed -4.5 and the torque arm +2.0 for a finial pinion angle of 2.5, right?
We used the outer holes on the bracket (the ones on the passenger side)
I have the UMI adj torque arm, Pacesetter longtubes, pacesetter Y pipe and a Dana 60 rear end with a big strange 3.5" DS. The car is stock ride height
The problem is on launch, I hear a vibration and a noise from the back of the car..almost like it's hitting something. I took the car up to 115mph and it was vibe free. it seems to just have issues with the launch. around half way through second the sound and vibration will go a way.
We used the outer holes on the bracket (the ones on the passenger side)
I have the UMI adj torque arm, Pacesetter longtubes, pacesetter Y pipe and a Dana 60 rear end with a big strange 3.5" DS. The car is stock ride height
The problem is on launch, I hear a vibration and a noise from the back of the car..almost like it's hitting something. I took the car up to 115mph and it was vibe free. it seems to just have issues with the launch. around half way through second the sound and vibration will go a way.
Last edited by Ziptie; 11-20-2006 at 11:07 PM.
11-21-2006, 09:43 AM
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you want a driveline angle of as close to 0° as possible.
in other words, your tranny output shaft angle and pinion angle should be roughly the same. Don't pay any attention to what angle your driveshaft is at. Measure the angle on your pinion (with the suspension loaded) and also the angle of your crank pulley (which is normal to your tranny output shaft). Adjust your TA so these two angles are roughly the same.
http://www.streetissuecustoms.com/pinionangle.html
https://ls1tech.com/forums/showthrea...t=PINION+ANGLE
https://ls1tech.com/forums/showthrea...t=PINION+ANGLE
in other words, your tranny output shaft angle and pinion angle should be roughly the same. Don't pay any attention to what angle your driveshaft is at. Measure the angle on your pinion (with the suspension loaded) and also the angle of your crank pulley (which is normal to your tranny output shaft). Adjust your TA so these two angles are roughly the same.
http://www.streetissuecustoms.com/pinionangle.html
https://ls1tech.com/forums/showthrea...t=PINION+ANGLE
https://ls1tech.com/forums/showthrea...t=PINION+ANGLE
11-21-2006, 01:36 PM
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Need the car on road-like footing. I used 4 Rhino
ramps, equal all around.
The only way that worked for me was to get it
set up to zero driveline angle first. That is not
so hard to keep straight, keep the angle finder
pointed toward the nose and get the same angle
on the pinion flat as you got on the trans pan.
Then you go and dial the pinion nose down by a
degree (poly / hard links & stiff arm) or two
(factory rubber).
ramps, equal all around.
The only way that worked for me was to get it
set up to zero driveline angle first. That is not
so hard to keep straight, keep the angle finder
pointed toward the nose and get the same angle
on the pinion flat as you got on the trans pan.
Then you go and dial the pinion nose down by a
degree (poly / hard links & stiff arm) or two
(factory rubber).
11-23-2006, 11:17 PM
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Ends up the torque arm was hitting the rear drivers side passenger floorpan, which was my vibration/noise. Also, the angles I gave above we found out is actually 6 degrees of pinion angle...not 2.
Last edited by Ziptie; 11-23-2006 at 11:22 PM.
