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View Full Version : How to set driveline pinion angles



4.3LXJ
05-15-2011, 01:22 PM
Since I am not a member, and since you do not have an official post on how to set driveline pinion angles, I thought I would post here. Driveline pinion angles come up often and I get tired of going through the same thing repeatedly, so I thought a post was in order so we would all have access to this information. It is also easier for me to just give a link to our own website. So here it is.

It is not all that hard. You just need to do what professionals do. I have done this many times. First, you need to purchase an angle finder, or if you have an Android, download an angle finder app. The angle finders are cheap and look like this:

http://i649.photobucket.com/albums/uu215/warriorsuspension/IMG_0941.jpg

The pic above shows you how to measure off the pinion. Then place the angle finder on the the fill plug or any other vertical machined surface on your transfer case and measure that. Next, what you do depends on whether or not you have a SYE or standard set up.

If you have a standard setup with a stock tcase, your driveline geometry needs to like like this:

http://i649.photobucket.com/albums/uu215/warriorsuspension/2joint_angle.gif

If this is the case, you will subtract one value from the other and that is the number of degrees you need to change the pinion. It needs to match as close as possible the angle on the tcase. This can be done with shims, or if you have not welded your spring purchases you can rotate the axel housing till you get the right angle and then tack weld them in place.

If you have an SYE (slip yoke eliminator) and a double cardan U joint on the tcase end of the driveline, then the geometry you need is this:

http://i649.photobucket.com/albums/uu215/warriorsuspension/cv_angle.gif

To get this, loosen the ubolts and place a jack under the pinion and raise the pinion until the driveline angle is the same as the pinion angle, or an easy way to put it is just raise it until the pinion U joint has no angle to it. It needs to look like this.

http://i649.photobucket.com/albums/uu215/warriorsuspension/IMG_0295.jpg

Measure the new pinion angle and then subtract the first value from the second and then that is the amount of shim you need, or if you have not welded the spring pads then tack weld them in that position.

As long as you have not exceeded the angle the U joints will accommodate without the yokes hitting, you will have vibration free driving.

4x4Dalton
05-15-2011, 05:15 PM
Great info man. Thanks alot!!

modestmar00xj
05-30-2011, 02:02 AM
very interesting! thanks for the post!

Mudderoy
08-08-2011, 03:23 AM
Ok I remembered to check this before I put the rear drive shaft back in.

The yoke is 15 degrees and then measuring from the shaft of the transfer case is 5, maybe 6 degrees. So I'm only 10 off!!!!

Do they make shims specifically for aligning the axle? Standard parts places? I'll ask O'reily's when I return the starter core tomorrow.

I guess it's 15 degrees because of the rear shackle...

4.3LXJ
08-08-2011, 06:01 AM
Tony.

It is not the angle of the shaft since you don't have an SYE. It is the angle of the transfer case yoke compared to the angle of the pinion yoke.

msmoorenburg
08-08-2011, 06:40 AM
Rough Country sells the shims. I would wait till you do a SYE to shim it. I know mine is wrong but the plan is to a bastard pack and shim it to get rid of the blocks. Also I had no real choice on the SYE due to the slip yoke drive shaft play. You can see i'm way out


http://i7.photobucket.com/albums/y299/msmoorenburg/IMG_20110719_193428.jpg

Mudderoy
08-08-2011, 08:56 AM
Tony.

It is not the angle of the shaft since you don't have an SYE. It is the angle of the transfer case yoke compared to the angle of the pinion yoke.

Hmmm so the end of the shaft coming out of the transfer case, the flat end that is perpendicular to the ground isn't the same as the back of the transfer case?

4.3LXJ
08-08-2011, 09:48 AM
Yes, it should be. You can just measure the flat machined part of the tcase. If you had a 10° difference between that and the angle of the face of the yoke then you would have a vibration so bad you could not stand it. I don't want to be confusing about this. The two angles need to be as close as possible.

Mudderoy
08-08-2011, 09:59 AM
Yes, it should be. You can just measure the flat machined part of the tcase. If you had a 10° difference between that and the angle of the face of the yoke then you would have a vibration so bad you could not stand it. I don't want to be confusing about this. The two angles need to be as close as possible.

I'll measure it tonight, and take some picture so we can see if I'm doing it right.

I agree I figured the vibes would be pretty bad with that big a difference. But they are not... A mystery!