Front axle U-joints, Need replacing

I think I need to replace my front axle U-joints. 91 Cherokee Laredo 4.0, Dana 30 front axle.

The front end has been making a rattle noise kind of on and off for a while. First it sounded like the noise was coming from the drivers' side only. Noise would quiet or go away at speeds about 30mph. Got underneath could not find anything loose, Front wheels didn't have any play in them. A couple of days ago the noise started coming from the passenger side. Got uderneath and found that the front-wheel axle U-joints had some play in them and raddled some to.

So I think this is the source of my front end noise. And I assume they need replacing. What do you think? I not a stranger to a wrench, but I am not a mechanic either.

Has anyone done such a repair? What is involved? Parts needed? Tools needed? Does the front axle need to come off?
I did some searching, but could not find anything in detail.

Help!

<grin> You need to search a little more, this is a pretty common maintenance item. </grin>

Having said that, for tools and stuff out of the ordinary, you'll need a 36mm socket for the axle nut, and a 12 point 13mm socket for the hub bolts. You may need an Allen wrench for the brake calipers, it varies a little. You'll also need 2 replacement cotter pins for the axle nut keeper, and I'd suggest a couple of sacrificial bolts for the hubs. And a couple of torque wrenches, one that goes to 175 ft./lbs. Oh yeah, you'll also need a u-joint press or a couple of big sockets and a sledge to replace the actual u-joint.

Put the XJ in 4wd, leave it in gear (or PARK with a slush box,) set the parking brake, and securely chock the rear wheels. Jack up the side you're working on , and remove the wheel. Remove the 2 bolts holding the caliper on, and secure it out of the way (DON'T hang it by the brakeline!) Remove the rotor.

Remove the cotter pin in the axle nut keeper, and remove the keeper, washer and the thrust spring (if there.) Remove the axle nut. This is where the XJ absolutely, positively, must be secured, this nut is torqued to 175 ft./lbs.

At least loosen, if not remove, the 3 hub bolts in the back of the knuckle. I keep a set of sacrificial bolts for this. Thread out the bolts so that they have 1/4" to 1/2" of free space showing under the head. Beat the daylights out of the 2 lower bolts (you can't get a swing at the top one, it's inside the C) until the hub comes loose. Alternative methods include using a cold chisel at the split, or by using a slide hammer on the wheel studs. I refuse to use a slide hammer as that pulls on the inner race, when it's the outter race that is held in place.

Once the hub is removed, you can slide the axle out and replace the u-joint.

These are inner clipped u-joints, you need to remove the inner clip (they'll probably come out in pieces) and then push the u-joint through one yoke. Remove the exposed cap, and you should be able to get the rest of it loose. Be very careful to not compress or expand the yokes if you're using a press.

To reassemble the u-joint, reverse the process. Remove the caps from the new u-joint, being careful to not drop any of the needle bearings (trust me, this can ruin your day.) Finagle the cross into one yoke, and start to slide a cap over one ear. Use the press (or socket and sledge) to seat the cap, and then do the other side. Repeat for the other 2 caps.

Now is the time to clean all of the mating surfaces, bolts, etc. and give them a good coating of NeverSeez. Give the splines on the end of the axle shaft some bearing grease.

Insert the axle back into the tube, being careful to support the axle through the seal at the diff. Don't let it drag on the bottom of the tube, you'll likely push some crud through the seal into the diff, or roll the seal over.

Mount the hub back up, not forgetting the dust shield (and getting it in the right orientation.) It'll take some work to get everything to line up, but trust me, it will. Replace the 3 bolts and torque to 75 ft./lbs.

Torque the axle nut down to 175 ft./lbs. This is *IMPORTANT*. If you don't have enough preload on the bearing, it will fail.

Replace the washer, thrust spring and keeper on the axle nut, and use a new cotter pin to keep it together.

Mount the rotor, and remount the brake caliper. Remount wheel.

No, it's not commonly done. I've only done mine, and a YJ and 2 more XJs for friends.

ChiXJeff

Now that is detail! From my description, does it sound like the front axle
u-joints?

Thanks a million !!!!!!

BskisXJ said:

Now that is detail! From my description, does it sound like the front axle
u-joints?

Thanks a million !!!!!!

Click to expand...

Your description is indeed a description of bad u-joints. There should be no play or rattle in them.

Well looks like I have a little work to do.
Doesn't sound too bad though. At least the u-joints aren't expensive. Just time and labor.

Thanks!!

A 91...... and I'm going to assume that the hubs have never been taken out.

I'd strongly suggest getting some sacrificial bolts to remove the hubs, that's the most time and effort effective way I've found to get them out. You *WILL* round over the heads when you beat them out. If they've never been out, expect to whale away on them for quite a while. Once you hit them up with some NeverSeez, they'll come out pretty readily.

The hub bolts are also one of the few places that I won't use anything but OEM bolts. These suckers are harder than anything you'll get at the hardware, and there is a profile to them. You can use hardware bolts as the extractors, though, I just don't remember what size.

Jeff - do you mind if I copy that procedure to my webpage? It's one of the more detailed versions I've read and I have a feeling I'll be able to add some pictures to it before too long...

Permission is given, feel free.

Cool. Thanks.
Jim

I'm going to add one more possible method for popping the hubs loose.

Caveat: I have *NOT* personally tried this. It should work, it sounds reasonable.

You'll need longer sacrificial bolts in the 2 lower hub holes, long enough that they'll contact the C when the steering is swung over. Without putting the XJ in gear OR stepping on the brakes (you'll pop the piston out of the caliper and ruin it!) gently turn the steering wheel left and right to just pop the hub loose. As soon as the hub starts to come loose, straighten up the steering and go back to the sledge hammer to get it all the way out.

I suspect that you could rather easily bend over the sacrificial bolts doing this, so be forewarned.

I would only do this as a matter of last resort.