redneckfive

How do you measure to find out what kind of shims or degree blocks you need?

4.3L XJ

The first thing you do is buy an angle finder. About 10 - $20. Then you have to measure the angle on the tail shaft on the transfer case and the pinion on the diff. subtract one from the other and use that number of degrees on the housing spring perches to make the angles the same. It need to look like this.



If you have an SYE, you measure the pinion, loosen up the ubolts and aim the pinion at the tcase tail shaft and measure again. subtract one from the other and use that shim. It needs to look like this.

redneckfive

Thanks I will figure it out from there.

Mike1998XJ

It looks like the drawing has the DS in-line with the TC. Don't you want the pinion 2 degrees (+/-) less than straight-on when running an SYE?

4.3L XJ

Mike. This is direct from Tom Woods website. If a leaf spring is flexy enough to shift 2* while driving on the highway, deceleration would put it out by 4* which might be enough to cause a vibration. I set mine up like this diagram and it works fine with my bastard pack.

Mike1998XJ

Sounds good... I guess close enough must work... I cut my perches off and re-welded them with the pinion 2 degrees down to allow for axel wrap and I don't have vibes either. Had to go with the ruffstuff diff cover to make sure I had enough fluid to keep the pinion bearing from starving for oil. The ruffstuff comes with the fill-plug moved up 3/4" so it makes it easy.
Mike

98xjeeper

So with a C.V. DS, the pinion and DS should be straight?? If that is the case would I be able to take a straight edge and measure the thickness ( or gap between the straight edge and the shaft ) and just get a shim that thickness?? I know this may sound stupid but I have limited resources and am new to jeeps. Thanks for the help.

4.3L XJ

It should look like this.



The way to really do this is with the angle finder like I mentioned. They are not expensive and if you miss it the first time, you paid for it.

redneckfive

so if my transfer case is at 2 degrees and my driveshaft is at 21 degrees and my differential is at 4.5 degrees. what degree block or shim should I get to straighten out my pinion angle issue?

4.3L XJ

Yoiu need a 2* shim. Drive line angle is not relevant.

4.5* - 2* = 2.5*