Pinion Angle Question
This thread is great! I have been adjusting and adjusting my pinion angle and the vibration in the rear is better but i wasn't 100% sure what to set it to and eliminate all vibrations. Last night I went off the tranny tail shaft, and was off a few degree's so I'm hoping putting it to equal but opposite angles will eliminate vibrations.
Thanks for all the guys posting and putting up the pictures. Those help a lot!
Thanks for all the guys posting and putting up the pictures. Those help a lot!
generally on the f-bodies the rear pinnion should be at zero or -1 ( pointing down). the trans will be pointing down a couple of degrees from the factory.
I agree with trying to get them inline (neutral ) but you should never have to adjust the pinion up (positive) if you do then never more then +1
have you had the shaft checked for balance and straightness?
Torque arm cars are different then the other type of rear suspensions.
I agree with trying to get them inline (neutral ) but you should never have to adjust the pinion up (positive) if you do then never more then +1
have you had the shaft checked for balance and straightness?
Torque arm cars are different then the other type of rear suspensions.
generally on the f-bodies the rear pinnion should be at zero or -1 ( pointing down). the trans will be pointing down a couple of degrees from the factory.
I agree with trying to get them inline (neutral ) but you should never have to adjust the pinion up (positive) if you do then never more then +1
have you had the shaft checked for balance and straightness?
Torque arm cars are different then the other type of rear suspensions.
I agree with trying to get them inline (neutral ) but you should never have to adjust the pinion up (positive) if you do then never more then +1
have you had the shaft checked for balance and straightness?
Torque arm cars are different then the other type of rear suspensions.
It comes down to what ever works best for your combo.
Yes zero or -1 down. The rears on these cars really don't climb like a leaf spring car. the torque arm keeps them from rotating as well as the coil springs. Most of the cars that see dual duty set them at -1 and don't worry about the trans or drive shaft. As long as the drive line angle isn't greater then 7 degrees total it will be ok. It seems most guys are confusing the whole drive line angle with just the pinnion angle.
It comes down to what ever works best for your combo.
It comes down to what ever works best for your combo.
If your tail shaft is down 4 degrees (relative to planet earth), and you set your pinion down 1, and under acceleration for some reason you only get 1 degree of climb (getting you level with earth at the pinion, 0 degrees), that's not ideal. The oscillation, change in speeds twice per revolution, strains the transmission, pinion bearing, the vibration loosens up the seals causing leaks.
Ideally you'd have as little difference between the front and rear joint angles as possible, under all operating conditions. I hate the +/- nomenclature, but if +, meaning pointing towards the dirt, and - means pointing toward the moon, the trans is +2, and the diff -2, then you have 2-2=0.
Last edited by lees02WS6; Aug 23, 2012 at 05:09 PM. Reason: grammar
Um not to argue with you 1lejohn but what you are saying is exactly opposite of what is posted earlier in this thread. They are saying for drag racing to set your pinion up like you are suggesting at -1 degree's.
however for street cars and to reduce vibration to point the pinion up, thus the equal but opposite thing. On my car the trans output shaft is pointing down 2 degree's, thus to get the face of the pinion yoke parallel I set my pinion pointing up 2 degree's. This is how you make the angles equal but opposite.
however for street cars and to reduce vibration to point the pinion up, thus the equal but opposite thing. On my car the trans output shaft is pointing down 2 degree's, thus to get the face of the pinion yoke parallel I set my pinion pointing up 2 degree's. This is how you make the angles equal but opposite.
Um not to argue with you 1lejohn but what you are saying is exactly opposite of what is posted earlier in this thread. They are saying for drag racing to set your pinion up like you are suggesting at -1 degree's.
however for street cars and to reduce vibration to point the pinion up, thus the equal but opposite thing. On my car the trans output shaft is pointing down 2 degree's, thus to get the face of the pinion yoke parallel I set my pinion pointing up 2 degree's. This is how you make the angles equal but opposite.
however for street cars and to reduce vibration to point the pinion up, thus the equal but opposite thing. On my car the trans output shaft is pointing down 2 degree's, thus to get the face of the pinion yoke parallel I set my pinion pointing up 2 degree's. This is how you make the angles equal but opposite.
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Brett Foote As long as they are in the 7 degree window. Look I punish my car on a daily basis. I've run the stock alum. shaft for years with no problems. I switched to a used metal matrix shaft and again no problems. The car has seen many 130-180 mph runs. I've had zero u-joint problems or failures..
Vibration LOL with the cam and exhaust that I run the whole car shakes...
I agree the neutral postion of the the two is best within reason. If your trans is at a 3 and you raise the pin to a 3 and the rear rotates up 2 more then the joints are in a bind. With a low HP car not on sticky tires it probally won't. A high HP car on slicks will. Or a stock car with the sloppy stock suspension will. Again if your looking for the velvet smooth ride then inline at what ever angle it takes is ok. Good discussion.
Vibration LOL with the cam and exhaust that I run the whole car shakes...
I agree the neutral postion of the the two is best within reason. If your trans is at a 3 and you raise the pin to a 3 and the rear rotates up 2 more then the joints are in a bind. With a low HP car not on sticky tires it probally won't. A high HP car on slicks will. Or a stock car with the sloppy stock suspension will. Again if your looking for the velvet smooth ride then inline at what ever angle it takes is ok. Good discussion.
Staging Lane
Joined: May 2012
Posts: 71
Likes: 0
From: Denmark
The thing about universal (cardan) joints is that in actual fact it seems they cannot really operate at an angle. What I mean by that is a single u-joint will only produce constant velocity, vibration free, when it is not at an angle to the yoke or the shaft it’s attached to. The moment you apply an angle it will cause the shaft to wobble, as the joint angle increase so does the wobble or vibration.
A standard drive shaft, with a u-joint on each end, will only produce a constant velocity when those two joints are parallel to each other. Forget the number of degrees, they are a reference, if the car’s nose is up in the air or buried under ground the relative number of degrees between the transmission output shaft, and the yoke at the pinion is what is important.
Anything other than compensating angles (at least close any way) will produce bearing killing, u-joint wearing, pinion seal leaking shake and break.
It seems to me that the reason people are given the suggestion to run opposing angles of any degree is to compensate for pinion rotation. In a drag race when its power on through the whole quarter mile, the pinion will rotate up.
If you have 3° down at the tailshaft of the transmission, then you want 3° up at the pinion while power is being applied. If you have 3° of rotation when power is applied, and started with 3° of static alignment at the pinion, you’d have 6° up of pinion angle with all the juice applied (way too much).
The idea for drag racing it seems is, you start with a lower number at the pinion yoke (opposing angles), and under power it will rotate up to the compensating angle. The V (often called broken back config or W) config is that driveline angle where both angle are opposing.
For other types of driving you want equal opposite angles, second diagram down. The third diagram will make vibration worse in all cases, except drag racing.
A standard drive shaft, with a u-joint on each end, will only produce a constant velocity when those two joints are parallel to each other. Forget the number of degrees, they are a reference, if the car’s nose is up in the air or buried under ground the relative number of degrees between the transmission output shaft, and the yoke at the pinion is what is important.
Anything other than compensating angles (at least close any way) will produce bearing killing, u-joint wearing, pinion seal leaking shake and break.
It seems to me that the reason people are given the suggestion to run opposing angles of any degree is to compensate for pinion rotation. In a drag race when its power on through the whole quarter mile, the pinion will rotate up.
If you have 3° down at the tailshaft of the transmission, then you want 3° up at the pinion while power is being applied. If you have 3° of rotation when power is applied, and started with 3° of static alignment at the pinion, you’d have 6° up of pinion angle with all the juice applied (way too much).
The idea for drag racing it seems is, you start with a lower number at the pinion yoke (opposing angles), and under power it will rotate up to the compensating angle. The V (often called broken back config or W) config is that driveline angle where both angle are opposing.
For other types of driving you want equal opposite angles, second diagram down. The third diagram will make vibration worse in all cases, except drag racing.
I am having a driveshaft with a U joint in the middle, and my car is vibrating like hell. I guess it is because the former owner of the truck lowered the car by the front mounting of the leafsprings. He mounted them higher onto the frame, and that means my pinion angle is pointing more upward that it should...
Can I fix this by simply put some shims between frame and the crossmember that is supporting the driveshafts U joint ?
The last diagram, have you tried that one?
I am having a driveshaft with a U joint in the middle, and my car is vibrating like hell. I guess it is because the former owner of the truck lowered the car by the front mounting of the leafsprings. He mounted them higher onto the frame, and that means my pinion angle is pointing more upward that it should...
Can I fix this by simply put some shims between frame and the crossmember that is supporting the driveshafts U joint ?
I am having a driveshaft with a U joint in the middle, and my car is vibrating like hell. I guess it is because the former owner of the truck lowered the car by the front mounting of the leafsprings. He mounted them higher onto the frame, and that means my pinion angle is pointing more upward that it should...
Can I fix this by simply put some shims between frame and the crossmember that is supporting the driveshafts U joint ?
Can you loosen the leaf spring clamps on the axle and rotate the pinion down?
Staging Lane
Joined: May 2012
Posts: 71
Likes: 0
From: Denmark
Thanks for reply..
I already fixed it myself... Made som wedgeshaped alu-blocks with 4 degrees.. That help alot... But I think I might do 1-2 degrees more...
https://ls1tech.com/forums/gears-axl...-20-25mph.html
I already fixed it myself... Made som wedgeshaped alu-blocks with 4 degrees.. That help alot... But I think I might do 1-2 degrees more...
https://ls1tech.com/forums/gears-axl...-20-25mph.html
generally on the f-bodies the rear pinnion should be at zero or -1 ( pointing down). the trans will be pointing down a couple of degrees from the factory.
I agree with trying to get them inline (neutral ) but you should never have to adjust the pinion up (positive) if you do then never more then +1
I agree with trying to get them inline (neutral ) but you should never have to adjust the pinion up (positive) if you do then never more then +1
