PLEASE HELP!!! Pinion angle/vibration question?
PLEASE HELP!!! Pinion angle/vibration question? I installed a bmr adj. ta and set the pinion angle (off the pinion only) to -2 (down towards ground). All was fine for about 10 days/300 miles, serious vibration started 55mph on up. Did some more reading and checked the angle on the trans -4 deg. (4 deg. down at tail shaft) so i then set the pinion angle to +4 deg. (now both angles are equal but opposite trans -4/pinion +4) Vibration is still there. So i replaced the u joints/tried another ds/clecked ballance on wheels and the vibration is still there!!!
At this point the only thing left that i can think of is i still have the pinion angle wrong? or its some thing in the rearend?
(all the angles were checked on a drive up lift that was level)
what do you think b & c angles should be? or is it something else?
thanks,
doug
At this point the only thing left that i can think of is i still have the pinion angle wrong? or its some thing in the rearend?
(all the angles were checked on a drive up lift that was level)
what do you think b & c angles should be? or is it something else?
thanks,
doug
'B' & 'C' are the ones to be concerned about and measured.If you're after a -4 degree setting,the difference of angles between 'B' & 'C' should be 4.-4 if the pinion is pointing downward in relation to the driveshaft,+4 if the pinion is pointing upward in relation to the driveshaft. you could set for -2 and see if vibrations still exist.If vibrations are gone,then you know you heading toward the proper setting.A -(minus)figure is desirable as axle/rearend torque rotates the housing upward to a +/- situation.
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Do not go by the transmission. Pinion angle is set in relation to the driveshaft and rear end yoke. Your driveshaft (stock form) should be 1.5* neg.(down). W/ the BMR trans mount torque arm, set your rear end yoke @ 90*. This will give you a pinion angle of 1.5* which is accecptable w/ your set-up. Also, driveshaft should be in transmission tailshaft all but a 1. to 1.5, or vibration could occur. Use a quality pinion angle guage. (craftsman)
How do you change that? I can't figure out for the life of me how to get rid of it... it's driving me nuts and tearing my synchros apart at the top end of the track. I figure it's the next step in trying to solve this friggin problem.
