TheSloMoShow

Good evening!

First, I'd like to thank the forum for the wealth of knowledge I have found within. I bought myself a used 2001 XJ with 155K on the odo about a month back. I knew it needed some work, but once bought and once I started to drive found it needed a bit more than I originally thought. In the end I ended up working out the following.

Fluids change (engine,tranny,both diffs, coolant)
Replaced front wheel hubs, and u-joints
New tranny filter
Replaced EVAP system hoses & fittings to end my EVAP system CEL
Replaced O2 sensors
New plugs and wires
Freshen up all grounds (amazing the difference this had!)
Fix "NoBus" dash cluster issue
Replaced IAC, IAT and cleaned TB butterfly (much smoother idle now)
Replaced headliner and new stereo/speaker install
Some other minor things to help the XJ "run right"

Thankfully, I haven't had to make a single post on this forum until now.
I'm having a bit of a whine (sounds like a bad bearing) and also a "clunk" from my rear end drivetrain when I let off gas pedal and/or right when I get back into it and accel again.

I was in the process of re-greasing my slip-yoke splines this weekend at the transfer case but upon reassembling ended up snapping one of the u-joint strap bolts right off flush with the face of the pinion yoke. Also, at the same noticed that my yoke seal is leaking on the diff. So.....

I bought a new Chryco 8.25 pinion, pinon seal, nut and u-strap and bolts. But 2 questions still remain, hopefully the forum can point me in the right direction here.

1.) While I'm in there, is it necessary to replace the pinon bearing(s)? Replacing just outer, or would I need to replace both? Is the extra work to replace the bearings going to make much a difference? I've heard a bad seal is a result of a bad bearing(s), but that when replacing bearings I have to mess with resetting the gears etc.....so IDK what stance to take.

2.) What's the easiest way to 'lock' the yoke in place while trying to remove the nut? I have an air impact wrench so I should have enough force to remove the nut. But I don't want to ruin any of the gears inside letting the gears act as a place lock for the pinion yoke. Also, if my wheels are off the ground I don't know how I'll get enough force (by say a pipe wrench) on the yoke to hold it in place countering the force of the impact wrench (which is most likely 150-200lbs-ft of force).

Thanks in advance for any help!

93XJeeper

there's more to it than just sliding a yoke on and off. There's is a pinion bearing preload and a crush sleeve that needs to be replaced. You will need to do the gear paint, gear backlash and all that stuff too.

TheSloMoShow

I have a pretty firm understanding of how setting the preload works (forgot to mention, bought new crush washer as well) if only removing the yoke and replacing seal....but had 2nd thoughts about bearing replacement as this would involve removing the pinion itself I believe if replacing both bearings?

93XJeeper

I would just leave it unless your having problems with the existing bearings

TheSloMoShow

Understood, I'll probably leave the bearings alone.

How to lock the yoke in place though?

Like I said I've seen members mention a pipe wrench, but I can't see how you would put this in place such that it'll counter the force of the impact removing the nut (or vice versa when putting the nut back on).

md21722

Holding the yoke steady with an impact is easy with a pipe wrench. One hand has the pipe wrench and one hand has the impact. There is so little force on that pipe wrench, all you're basically doing it holding it from free wheeling. You are not counter acting the full force of the impact. If doing it by hand, you generally need a longer pipe wrench or a cheater bar for it so it can dig into the concrete floor or whatever.

But the real problem here is that your differential is leaking, has a problem yoke, and also whines.

Unless you have a keen interest in learning how to set up differentials and spend a lot of time and money, your best bet is to get a good one from someone on craigslist or the junk yard. Here in Colorado where XJ's are on every street corner and people are upgrading every day, stock 8.25 axles cost about $100 and Dana 35 axles drum to drum are routinely scrapped or no more than $50.

For a full rebuild... concepts like backlash and pinion preload must be understood before you start taking things apart. You should have a beam type or Torqometer style torque wrench to measure the pinion preload. You should have a way figured out to tighten a crush sleeve to over 300-350 pounds. You will also need tools to drive out (and then back in) the pinion bearing races, and pull off and push on the carrier bearings. And then make or buy the special tool for the side adjusters to set backlash. You might think the bearing race driver installer set you bought for hubs 20 years ago that's still on your shelf will work great until you realize that carrier housing is deep and you need a longer handle. And using a punch or chisel to drive those races out will be time consuming laying on your back. There are special tools that make things easier, but they are not cheap.

TheSloMoShow

I could have specified more, the "whine" actually comes from the front end (I'm thinking front driver side wheel bearing) although the clunk definitely is coming from the mid/rear.

I actually just got done replacing the pinion seal and yoke an hour ago, wasn't too bad of a job with an air tool and inch/lb torque wrench. Getting the preload set right is a bit tough since there isn't a whole lot of room for error, but I believe I was able to get it right. With wheels and drums off the load feels just the same before/after.

After having driven around a bit there still is a light clunk letting off pedal in OD, but it isn't too bad and greasing the splines by the transfer case through the nipple I just added seems to help somewhat.

I'm no expert on checking bearings so can't speak to the condition of my bearings on the pinion, but I'm willing to take the chance with not replacing these for now. I'll check the seal periodically and if it starts to leak again, or any sound gets worse coming from the diff then I'll have to take it to someone who knows a good bit about gear setup.

Thanks for the help, using the pipe wrench certainly was much easier than I thought!