Pinion angle????????
I am having bad vibrations/shaking at high speeds on the highway. this happened after I put a bunch of new things in the car, but particularly after I put in a new custom driveshaft and the adjustable torque arm. I have my pinion about -2. Could the pinion angle cause the shaking or is my driveshaft maybe out of balance???????
Uneven angles at the U-joints contribute to vibration.
If you point the pinion down severely, you may need
to point the trans tail up to compensate it (getting to
zero or at least less driveline angle). But I don't see
a whole lot of folks doing it. Still a piece or three of
1/8" aluminum shim plate between the trans mount
and crossmember is a cheap enough thing to try and
see if the vibration settles down.
I think (but am not sure) that driveline angle vibe
will be felt more, the higher the driveshaft torque,
while balance doesn't really change except by speed.
This might help you distinguish the source. Like if it's
still doing it in neutral to the same degree, it's probably
balance related. At least I think so.
Sometimes people get lucky by rotating the driveshaft
180 vs the pinion yoke. The back could favor one way
or the other, for centerline / balance.
If you point the pinion down severely, you may need
to point the trans tail up to compensate it (getting to
zero or at least less driveline angle). But I don't see
a whole lot of folks doing it. Still a piece or three of
1/8" aluminum shim plate between the trans mount
and crossmember is a cheap enough thing to try and
see if the vibration settles down.
I think (but am not sure) that driveline angle vibe
will be felt more, the higher the driveshaft torque,
while balance doesn't really change except by speed.
This might help you distinguish the source. Like if it's
still doing it in neutral to the same degree, it's probably
balance related. At least I think so.
Sometimes people get lucky by rotating the driveshaft
180 vs the pinion yoke. The back could favor one way
or the other, for centerline / balance.
i wanted to check this for myself since i am a bmr guy and see madman always post vs. the ground
i just finished checking it both ways and BOTH WERE THE SAME -2.5*
how bout that? fwiw my car is lowered about 1"
one less reason why the car doesnt 60' a damn.
i just finished checking it both ways and BOTH WERE THE SAME -2.5*
how bout that? fwiw my car is lowered about 1"
one less reason why the car doesnt 60' a damn.
Originally Posted by jimmyblue
Uneven angles at the U-joints contribute to vibration.
If you point the pinion down severely, you may need
to point the trans tail up to compensate it (getting to
zero or at least less driveline angle). But I don't see
a whole lot of folks doing it. Still a piece or three of
1/8" aluminum shim plate between the trans mount
and crossmember is a cheap enough thing to try and
see if the vibration settles down.
I think (but am not sure) that driveline angle vibe
will be felt more, the higher the driveshaft torque,
while balance doesn't really change except by speed.
This might help you distinguish the source. Like if it's
still doing it in neutral to the same degree, it's probably
balance related. At least I think so.
Sometimes people get lucky by rotating the driveshaft
180 vs the pinion yoke. The back could favor one way
or the other, for centerline / balance.
If you point the pinion down severely, you may need
to point the trans tail up to compensate it (getting to
zero or at least less driveline angle). But I don't see
a whole lot of folks doing it. Still a piece or three of
1/8" aluminum shim plate between the trans mount
and crossmember is a cheap enough thing to try and
see if the vibration settles down.
I think (but am not sure) that driveline angle vibe
will be felt more, the higher the driveshaft torque,
while balance doesn't really change except by speed.
This might help you distinguish the source. Like if it's
still doing it in neutral to the same degree, it's probably
balance related. At least I think so.
Sometimes people get lucky by rotating the driveshaft
180 vs the pinion yoke. The back could favor one way
or the other, for centerline / balance.
The way I understand it is, the U-joints "like"
the front and back stubs to be parallel, this
minimizes the amount of wobble & scrub.
http://www.roddingroundtable.com/tec...driveline.html
http://www.drivetrain.com/driveline_angle_problem.html
http://www.4xshaft.com/driveline101.html
Google search for: pinion driveline angle joint
and you'll see a ton of fairly informative stuff.
A lot of it seems to be 4x4 oriented, those
guys really push the limits of U-joints. But it's
all the same issue.
the front and back stubs to be parallel, this
minimizes the amount of wobble & scrub.
http://www.roddingroundtable.com/tec...driveline.html
http://www.drivetrain.com/driveline_angle_problem.html
http://www.4xshaft.com/driveline101.html
Google search for: pinion driveline angle joint
and you'll see a ton of fairly informative stuff.
A lot of it seems to be 4x4 oriented, those
guys really push the limits of U-joints. But it's
all the same issue.
Originally Posted by -Joseph-
Thats the way I do it, although it may be recommended to verify that plate is 90deg from the actual yoke angle. I'm pretty sure its supposed to be, but machining operations may not be as 'dead nut' as expected.
Right now my "pinion" angle is zero in relation to level ground at ride height. My "driveline" angle is 3, so if I move the "pinion" angle to 3 also that would make this "driveline" angle 6 no load.....? But.....I'm thinking that the driveline angle would follow the pinion angle somewhat during adjustment since it will move also, while its 3 degrees now, with the pinion itself at 3 down it may only change 1/2 the difference, possibly 4.5 "DL" degrees instead. I know I'm probably overcomplicating things.
Right now my "pinion" angle is zero in relation to level ground at ride height. My "driveline" angle is 3, so if I move the "pinion" angle to 3 also that would make this "driveline" angle 6 no load.....? But.....I'm thinking that the driveline angle would follow the pinion angle somewhat during adjustment since it will move also, while its 3 degrees now, with the pinion itself at 3 down it may only change 1/2 the difference, possibly 4.5 "DL" degrees instead. I know I'm probably overcomplicating things.
I'm so confused
Originally Posted by SSnakekiller
I am having bad vibrations/shaking at high speeds on the highway. this happened after I put a bunch of new things in the car, but particularly after I put in a new custom driveshaft and the adjustable torque arm. I have my pinion about -2. Could the pinion angle cause the shaking or is my driveshaft maybe out of balance???????
I will have to balance the driveshaft and see if my vibrations disappear.
