Pinon Angle vibration
05-09-2017, 11:00 AM
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Staging Lane
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Pinon Angle vibration Setup is a 70 Chevelle, with LQ4 , TH400 with Gearvenders Overdrive , Ford 9 inch 1 with 1350 yoke, QA1 Adjustable coilovers.
I had slowly acquired a vibration at 75 mph then it got worse at 65 mph over a short amount of time. I figured out the rear upper adjustable control arms had come loose. I readjusted the angle and things got better. But i was still vibrating at 80 mph. So I used a angle gauge (which I should have done to begin with) to figure out that the rear was 9 degrees up and the Trans was 6 degrees down. I can only go 4 degrees down on the trans before it hits the floor at 3.5 degrees. I have read that the angles should be at 2 degrees in parallel. Should my setup be ok if I used 4 or 4.5 degrees instead. I have read that my yoke can handle about 30 degrees and is used by the off-road community a lot. Or should I yank the trans and make some more room by hammering some dimples into my floor?
I had slowly acquired a vibration at 75 mph then it got worse at 65 mph over a short amount of time. I figured out the rear upper adjustable control arms had come loose. I readjusted the angle and things got better. But i was still vibrating at 80 mph. So I used a angle gauge (which I should have done to begin with) to figure out that the rear was 9 degrees up and the Trans was 6 degrees down. I can only go 4 degrees down on the trans before it hits the floor at 3.5 degrees. I have read that the angles should be at 2 degrees in parallel. Should my setup be ok if I used 4 or 4.5 degrees instead. I have read that my yoke can handle about 30 degrees and is used by the off-road community a lot. Or should I yank the trans and make some more room by hammering some dimples into my floor?
05-10-2017, 07:45 AM
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I think that is too much and a source of your trouble. I would figure out a way to correct it. If Im understanding what youre saying you now currently have a positive pinion angle which is not good.
Remember you are shooting for the 2nd pic, equal or equal but opposite angles.
Measure Angle A and Angle B on the caps that stay flat.
Remember you are shooting for the 2nd pic, equal or equal but opposite angles.
Measure Angle A and Angle B on the caps that stay flat.
05-10-2017, 12:27 PM
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You might need angled leaf spring perch shims to correct the rear angle to 6 degrees. Start there and leave the transmission at 6 degrees
05-12-2017, 09:40 AM
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Staging Lane
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Darth, I have a ford 9 inch with coilovers and adjustable uppers. I can just move the uppers. No leaf springs.
SSRED, Thanks. I was wondering if 4 - 5 degrees was too much...
SSRED, Thanks. I was wondering if 4 - 5 degrees was too much...
05-12-2017, 10:21 AM
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Cool. I was thinking leaf springs and no torque arms.
05-22-2017, 08:24 AM
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I yanked the driveshaft and measured the angle (with tremic tools app on phone) on the end of the yolks, which was off about 1.7 degrees off on transmission from measuring from a point that I thought was perpendicular. Long story short i was measuring 2.8 degrees on trans yolk when it was 4.5. I also rotated the driveshaft on the pinion 180 degrees. At 93 mph its smooth as butter. I know my angle is a little steep but I dont want to pull the Gearvenders overdrive out to bang the tunnel up a little just yet.
What I cant get over is when I set everything up the first time, I had no idea about pinion and trans yoke angles and somehow I set it up pretty good on chance as I could hit 90 mph and not feel any vibrations. Beginners luck.
What I cant get over is when I set everything up the first time, I had no idea about pinion and trans yoke angles and somehow I set it up pretty good on chance as I could hit 90 mph and not feel any vibrations. Beginners luck.