Pinion angle, revisited...

Making sure you know that the pinion shaft needs to be pointed directly at the t-case output shaft. Just make sure its angle is not above the driveshaft either. 1-2 degrees under that of the driveshaft's angle is a good angle to aim at to counteract the minor effects of axlewrap on a coil spring TJ.

Jerry

Nathan Otis wrote:

Thanks Jerry... I'll probably drop the angle just a little more this weekend. I did know the pinion needs to be pointed at the output, but it's tough to see exactly where everything is pointed... n.

Jerry, How would one go about point the pinion shaft directly at the tcase output shaft?

I think I would try to use a string that followed the plane of the pinion shaft, and make sure I didn't break the plane by pulling the string at an angle. But, how would one find the plane of the pinion shaft to establish the line for the string?

An angle finder placed on the output shaft's u-joint gives the t-case's output shaft angle. Then the plane of the axle's pinion angle can be found with the angle finder placed at the rear of the axle housing on one of the two circular points which is perpendicular to the pinion shaft. Since the angle finder has two flat planes 90 degrees apart from each other, the angle finder can be rotated so it can be at the same angle it was when measuring the t-case output shaft. Then move the pinion up or down until it's at or 1-2 degrees under that of the t-case output shaft. At least that is how I get a pretty precise measurement on them. :)

Jerry

Jeff Strickland wrote:

Well.... That sounds _pretty_ percise ;-)

Thanks, n.

Use a cheap straight line laser... works perfect for this job. You can probably find one for under $10.

-Brian

Did you ever unhook the front driveshaft as was mentioned? Vibrations can come from sneaky places.....

Mike

Nathan Otis wrote:

Mike,

It seems counter intuitive that the vibes would be coming from the front, because 1. I haven't changed anything in the front and 2. I had to drive in

Still, if I can't get rid of it with control arm adjustments tomorrow morning, I'll try pulling the front shaft for kicks. Thanks for the tip. n.

You don't want to have any one universal joint not making enough bend- you'll get vibration (from the shaft going into an orbit) and short u-joint life (if the joint isn't bending far enough then the grease isn't able to do its job, it gets squeezed between all the needles and the needles beat dents into the cap and trunion.

IIRC, Spicer recommends a minimum 7 deg. angle to ensure grease distribution.

Also, if you drove this for some time with the rear shaft out, check that bearing in the transfer case- the output shaft might have been hammering the bearing due to the lack of load.

I take it you've got a new rear shaft there, are the yokes aligned?

John