Hey All,

I've been having bad vibrations on 92 XJ with C8.25 rear end. I noticed the pinion yoke has some wear on one of the tabs that holds the U Joint in place. One tab is thicker than the other. How hard is it to replace this part? Does it require special tools or can I just pull it off with impact gun and slide it right off? Any info and tips would be much appreciated.

 

Pinion preload is set by a crush sleeve and torque specification. Factory procedure requires measuring the rolling torque of the pinion before removal so you can set the same rolling torque on re-installation. Measuring and setting the rolling torque can be done with a beam type torque wrench or a Snap On Torqometer or similar. Click type torque wrenches cannot measure rolling torque.

 

YUP !!

 

thanks for the info. I was reading my repair manual. Says I would have to remove wheels and drums to measure the rolling torque with an inch-pound torque wrench, slowly turn the shaft to measure the amount of torque required to turn the pinion. Then Mark the relationship of the pinion shaft to the yoke. Has anyone done it this way?

 

I am not sure marking the relationship of the shaft to the yolk is a strict requirement. As far as removing the wheels and drums it makes sense to do it this way to get a more consistent reading. When I did mine, I had the axle on jack stands with the brakes off. You can hold the old yolk with a pipe wrench and a long pipe and use a breaker bar and long pipe to get the old one off and the new one back on. When you put the new yolk on and finger tighten the nut the yolk will probably have some slop in it. As you tighten that nut, you need to be very careful not to exceed the original rolling torque. Basically tighten in 1/4 turn increments and keep checkin the rolling torque. If you do, it means you changed the crush sleeve. Proper procedure would call for you to install a new crush sleeve if that happens. Google for You Tube videos on rebuilding a differential will give you a visual idea.

 

Do you happen to know the size of the Pinion nut??

 

1-1/4"

 

Cool, Thanks! I went to the junk yard and found a 97 with a 8.25 27 spline. This one should work being that my axle came out of a 96/97 XJ.

Would it be wise to replace the seal? Mine is not leaking at all. Can I just slap the new yoke on and torque it down with an Inch Torque Wrench?

 

You can replace the seal if you'd like. I didn't when I put in my Axle in. Rolling torque is the force required to keep the pinion turning. Not the torque on the nut to achieve it. It takes a big breaker bar to tighten that but enough to get the proper rolling torque. Watch some YouTube videos for a visual.

 

Awesome! Thanks for the info. I will have Inch Torque Wrench by tomorrow and I will watch videos today. I will post an update and pics when I'm done. Cheers!

 

Just wanted to send an update. The Yoke on the left is the old one. You can see where is it worn on the top.

 

Did it solve your vibration?

 

That's not wear, looks like someone ground the tab off.

 

Yep! When u joint was in there, there was like an eighth inch of slop/play. Now the u-joint seats perfectly. No vibrations at all.

 

Don't mean to hijack this thread, but my question is related.

Say you're a dope like me and didn't know about all these details when changing your yoke. How would one correctly redo this since you have no idea what the rolling toque was?