Ok, first let me start by saying that I have set many pinion angles before and i fully understand how do do it. I also have read over 20 threads on here about setting them so.............

I have had an aftermarket torque arm on for a while w/ 373 in the rear an i set the pinion angle myself at -2 (trans was -1 so I set my rear diff angle at -3 to give me a pinion or -2).

I had NO VIBRATION ever with this set up. I went to 410's and while it was in teh shop i asked the Mechanic to check the pinion angle (since they have a drive on lift and I did mine on jackstands) just for good measure.

When I picked the car up I was told the pinion was way off and that he adjusted it to -1 degrees. On the ride home... SHE BUCKED LIKE THE QUARTER HORSE AT THE FOOD LION!....

It was violent! I knew the pinion was off so I got under there the next day and it was +3!!!!! I set it to 0 just to test and went for a quick ride and it was better but not gone.

So today I readjusted it to -2 but the vibration didnt go away. I didnt have time to mess with it againg tonight so I still have to fiddle with it.

Oh and yes i already checked for a damaged drive shaft, buble in a tire, loose controll arm, busted trans mount, etc and nothing.

My question is, those of you that have an aftermarket torque arm, what is the angel of your rear housing relative to the level_ground. NOT your pinion angle in relation to the driveshaft or transmission but level_ground.

Anyother suggestions would be helpfull as well. Im trying to make it to the track Friday evening but dont want to (cant) go with a suspected incorrect pinion angle or i may snap my drive shaft. Besides its never smart to go over 100mph wiht ANY violent vibration.

thanks

 

If your tranny was -1,to zero it out it the rear would have to be +1.Then add the -2 which would = -1 at the rear total.This is of course with the car 100% level.If there is still vibration try 1 degree adjustments till it's gone.

Your problem though does not sound like a pinion angle deal unless it is still way off.Could be a loose pinion gear assembly.(pinion bolt not tight enough)

 

OK so what is the best way to get my trans angle then. Thats where i was having issues. Its so tight up there for the angle finder and nothing is really that flat to measure against. Where are you guys taking the trans angle from. I tried against the tailshaft but like I said, its tight in there with the torque arm and driveshaft.

I will also check the pinion nut today after work too.

Thanks again

 

http://www.rosslertrans.com/Tips/Pinon.htm

the best article i've found

 

Ill give it a third shot when I get home today, Thanks guys. I just hope the ring gear isnt out of balance. the VIbration is deffinitly drivetrain, as I get the vibration through the seats and through the shifter.

 

might be a bad trans mount or where the T/A mounts to the tranny also

 

The pinion angle and u-joint angle are different. The way you are measuring you are checking ujoint angle.

Pinion angle is checked with the car sitting at ride height. You use the pinion yoke and measure it versus the ground. The ground will be "0" down angle will be "-" up will be "+".

 

Exactly, that why I was asking people what there pinion angle was in reation to level_ground cause I was having a hard time getting an accurate reading from the trans and all F-bodies trans angle shoudl be within a degree of each other unless aftermarket trans mounts are used.

I do however need to get the pinion angle set in relation to the trans. Im going to give it another shot today but I think one of my biggest issues is the jackstands. There is no real way to have the car site like it would at ride height. I need a drive on lift like an exhaust or alignment rack.

THanks again for the replys guys! Wish me luck. I have to get this thing running right today so I can go to the track with my boy tomorrow with his 01 Cobra. We have been pretty even so far and I want to put an end to that!!!!!!!!!