Another pinion angle question
10-19-2013, 10:56 AM
#1
Another pinion angle question So I got my MWC 9" in and trying to get the angle correct. I've been over a bunch of threads and it seems like every thread has a different way to do it. Here's what I did.....
- Car was on 4 rhino ramps when checking with pinion angle finder.
- Facing the drivers side I put a square on the flat of the pinion and angle finder on the bottom of the square (per MWC instructions)....read exactly 0*
- Put angle finder on DS close to the u joint and it read 1* to the right of 0*.
Rear end has been centered with ADJ PHB prior to doing this if that makes any difference.
Suggestions on where to go next would be appreciated!!
- Car was on 4 rhino ramps when checking with pinion angle finder.
- Facing the drivers side I put a square on the flat of the pinion and angle finder on the bottom of the square (per MWC instructions)....read exactly 0*
- Put angle finder on DS close to the u joint and it read 1* to the right of 0*.
Rear end has been centered with ADJ PHB prior to doing this if that makes any difference.
Suggestions on where to go next would be appreciated!!
10-20-2013, 10:01 PM
#3
sounds like you might be confused with terminology. everyone should just do away with the term "pinion angle".
there are 2 things, (a) universal joint operating angle and (b) u-joint phasing.
a) wherever there is a u-joint there'll be an angle between the shafts on each side (which is the purpose of a u-joint). in your case transmission yoke to drive shaft, and drive shaft to pinion yoke. that measured angle between the two items connected to a given u-joint should be less than 5° but more than 0.5°. A u-joint is supposed to have a slight angle between the two shafts connected to it to operate properly. operating angle is usually never a problem on cars, it generally is on lifted trucks where there is a significant height difference between the transmission and rear axle.
b) phasing is what everyone here is concerned about. what it means is the operating angle of one u-joint needs to equal the operating angle of the other u-joint at the other end of the drive shaft. that means you are looking for a difference of 0°, or a phase angle of 0° which means they are in phase and won't vibrate.
you said "Put angle finder on DS close to the u joint".
for this measurement you never put an angle finder on the drive shaft.
it's better if you remove the drive shaft.
you measure the angle that the transmission yoke is pointing relative to the ground. you said "I put a square on the flat of the pinion and angle finder on the bottom of the square (per MWC instructions)....read exactly 0".
so it sounds like the car is pretty level and the transmission output yoke is pointing horizontal to the ground. so now you want to measure the angle the rear axle pinion yoke is pointing relative to the ground and adjust the torque arm so that measurement reads 0° (horizontal or parallel to the ground). now you're u-joints at each end of the drive shaft would be in phase. and to do this measurement it's better if you have the drive shaft removed.
and in your case since you happened to measure zero degrees for the angle the transmission yoke is pointing, you want to adjust your torque arm so the rear axle pinion yoke points downward somewhere between 0.5° to 2° or 3°. because you happened to get zero degrees for the transmission you don't have to do any math and hopefully things are obvious. the rear axle pointing down a little bit is what everyone refers to as pinion angle and you go downward a little bit to compensate for the tendency of the rear axle to want to rotate upward under load and account for whatever flex there may be in the torque arm bushings and such.
there are 2 things, (a) universal joint operating angle and (b) u-joint phasing.
a) wherever there is a u-joint there'll be an angle between the shafts on each side (which is the purpose of a u-joint). in your case transmission yoke to drive shaft, and drive shaft to pinion yoke. that measured angle between the two items connected to a given u-joint should be less than 5° but more than 0.5°. A u-joint is supposed to have a slight angle between the two shafts connected to it to operate properly. operating angle is usually never a problem on cars, it generally is on lifted trucks where there is a significant height difference between the transmission and rear axle.
b) phasing is what everyone here is concerned about. what it means is the operating angle of one u-joint needs to equal the operating angle of the other u-joint at the other end of the drive shaft. that means you are looking for a difference of 0°, or a phase angle of 0° which means they are in phase and won't vibrate.
you said "Put angle finder on DS close to the u joint".
for this measurement you never put an angle finder on the drive shaft.
it's better if you remove the drive shaft.
you measure the angle that the transmission yoke is pointing relative to the ground. you said "I put a square on the flat of the pinion and angle finder on the bottom of the square (per MWC instructions)....read exactly 0".
so it sounds like the car is pretty level and the transmission output yoke is pointing horizontal to the ground. so now you want to measure the angle the rear axle pinion yoke is pointing relative to the ground and adjust the torque arm so that measurement reads 0° (horizontal or parallel to the ground). now you're u-joints at each end of the drive shaft would be in phase. and to do this measurement it's better if you have the drive shaft removed.
and in your case since you happened to measure zero degrees for the angle the transmission yoke is pointing, you want to adjust your torque arm so the rear axle pinion yoke points downward somewhere between 0.5° to 2° or 3°. because you happened to get zero degrees for the transmission you don't have to do any math and hopefully things are obvious. the rear axle pointing down a little bit is what everyone refers to as pinion angle and you go downward a little bit to compensate for the tendency of the rear axle to want to rotate upward under load and account for whatever flex there may be in the torque arm bushings and such.
10-21-2013, 02:46 PM
#4
I got 0* at the rear yoke...I didn't know I was supposed to take a reading up near the trans..never saw that. I was basing my measurements off the BMR video and where they put the angle finders. I can't take my DS out without removing the TA with my duals.
Thanks for the response.
Thanks for the response.
