How to Change U-joints on a Dana 30
 

Tools you are going to need:
Jack
Jack stands
Lug-nut wrench
Socket or Wrench to remove the caliper bolts. Either a 7mm Allen Socket on Early models or a 10mm for later ones.
13mm 12-pt socket or wrench
36mm Hub nut socket
8mm flare nut wrench
Torque Wrench in the correct size drive for the hub nut socket
Vice, C-clamp or U-joint press.
Hammer
Long Breaker Bar(preferably 2 foot or longer)
Chisels, punches and drifts
Needlenose pliers
Small round file
Wire Brush or Emery cloth
Wire or wire coat hanger
Correct sized Cotter Pins
PB Blaster or other penetrating oil
Brake Cleaner
Never-Seeze
Shop rags
Safety glasses

A special thanks to Greg, my hand model.

This job really doesn't require any special skills or tools beyond what as a Jeep owner you really should have. But it requires the removal and reassembly of a couple of different things. So I give it two and half wrenches. Realistically, working alone you could complete this job in about 2 hours if you don't run into problems. Greg and I were working with an axle from a 89 that had seen no realistic maintenance in quite some time. Every thing was pretty frozen up and took some extra persuasion.

Step one.
Put your Jeep into 4 low and in park if an auto or in gear if it is a manual. This is to A. Keep your Jeep from rolling away as you work on it. B. We need the axle shafts not to turn freely when we remove the hub nut socket. Put on your safety glasses. Rust, time and corrosion will make things freeze together and in some steps they may come flying loose. Loosen your lug nuts before jacking the Jeep up.

Step two.
Jack your Jeep up and put it on jackstands that you can comfortably work on your Jeep. Remove your lug nuts and tire. Remove the brake caliper and hang it a piece of wire or a wire coat hanger. We don't want to let it hang from the brake line as that can damage the brake line. The brake rotor should slide off at this point. If it doesn't it might have some rust or crud built up around the wheel studs and take a few taps from a hammer to loosen up.

Now we can see this...
http://pic40.picturetrail.com/VOL267.../332559665.jpg

Step three:
There is a Cotter pin holding the cap on over the nut for the hub. Remove the cotter pin and cap. I have never been able to save the Cotter pins so I just replace them. Now we blast the hub nut and the three bolts that hold the unit hub to the steering knuckle with our penetrating oil. If you have a serious corrosion/rust issue this is where work will really slow down.

This is the thread end of one of the bolts holding the hub to the knuckle. There are two others spaced around the hub to keep it tight
http://pic40.picturetrail.com/VOL267.../332559653.jpg

Remove the hub nut. This nut holds the axle shaft to the hub. It will be VERY tight. Use the hub nut socket and breaker bar. On the drivers side of the test jeep we needed to use a three foot breaker bar and another 5 foot of cheater pipe to break this nut loose. Behind the nut there is a thick thrust washer, make sure not to lose it.

Now we remove the three bolts holding the unit hub to the steering knuckle.
These are 13mm 12-pt bolts. Trying to use a 6-pt socket or wrench will only destroy the head of the bolt and make it worse to get them out. There isn't much room to work in there as the picture shows.
http://pic40.picturetrail.com/VOL267.../332559658.jpg

When you have all the bolts out, comes probably the worst part of the removal process.

Step four: Removing the hub.

Now this is where you will get some debate on the best method to do it. There are a couple of different methods and I will talk a bit about a few of them. The first method is to use a three-jaw puller and attempt to pull the hub off. This is a REALLY bad idea for two reasons. First, in the center of the hub contains your wheel bearings, and if you pull apart the hub doing this you now have a bigger problem on your hand. Second when you are pulling on the hub, the center screw is sending all that force into the axle shaft. Which is attempting to force the shaft backwards into the carrier. The force isn't good on the carrier and you can also possibly damage the axle seal, which keeps your gear lube inside the differential and off the ground.
The second method is to put a socket extension or drift against the inside edge of the hub and steering knuckle and use the power steering to pop it off. This method does work quite successfully when it works. But there is the danger of that extension/drift popping out under load from the power steering and becoming a projectile.

The method I like to use is a hammer and chisel. Driving the chisel in around the edge of the hub will work the hub loose from its seat. This will generally take a while usually the hub is pretty well stuck in from exposure to the elements.

This is the position I start in:
http://pic40.picturetrail.com/VOL267.../332559671.jpg

Notice that I start on the ear where the bolts go through. In this area there is extra space where the hub doesn't actually set inside the knuckle. But DO NOT drive the chisel all the way into where the bolt holes are at. You can damage the bolt hole if you do.

When it comes loose the hub will pop out and you can slide the shaft out. Generally using the hammer and chisel method you will damage the dust shield beyond use. But if your Jeep sees any really kind of trail time, you might have already damaged it, or it serves only to collect mud,dirt and sticks off the trail and hold them next to your brake rotors.

When the hub and shaft are out it will look like this:
http://pic40.picturetrail.com/VOL267.../332559680.jpg

Step five: removing the U-joints.

There a couple of different methods for doing this also. I use a joint press that I bought from Harbor Freight for around $20. I know people have said they have had the C-frame crack and break on it. But I have done over 20 sets of U-joints using the same one, so if it breaks at this point I have gotten my money's worth.


While we are doing this we need to take care to make sure that we don't damage any of the splines on the shafts. These engage either the hub or the carrier inside of the differential, and we don't want to have to fix them. And if you have a vacuum disconnect axle, there is a small needle bearing inside the end of the shaft. Take care to protect that from damage and debris.
The first thing we need to do is remove the C-clips from the insides of the Joint caps. If we don't we can't drive the caps out of either side of the yoke.

We can see the small C-clip in this picture, Its just below the yoke side. It is the black piece. This picture shows a new joint in place. When you are trying to remove the old ones, they will be just as rusty as the rest of it and it was VERY hard to see them in the picture so I swapped this one in.
http://pic40.picturetrail.com/VOL267.../332559717.jpg

Now I use a press to slightly press one side of the U-joint in far enough to remove the C-clip on that side.
http://pic40.picturetrail.com/VOL267.../332559693.jpg

What we are doing there is pressing the entire joint over far enough to remove the C-clip on the screw side of the press. Once we have that C-clip out, we flip the shaft in the press and repeat the process. Press the joint far enough that you can remove the C-clip. Removing the clips is often a bit of trial and error. many times they are rusted in and you need to take a punch and drive them out from their edges.

Once we have the C-clips out, I like to remove the joint from the press and use a hammer and drift to remove the caps. I have seen joints that are pressed have caps explode and throw pieces everywhere, caps come completely out with a good deal of force throwing pieces of needle bearings all over. Even an occasional yoke crack from the force. also you can risk bending the ears of the yoke slightly making it much harder to get the joints back in.

Now take a drift and pound the caps through the outside of the shafts. You have to remove both caps for the cross to come out. There simply isn't enough room to do it other wise.

Once we have the joint completely out, take this opportunity to run a round file inside the ears of the yoke and both the inside and outside faces of the yoke. This is just to clean everything up so that there will be less difficulties getting the new joints in.

(Yea! We are onto the reassembly phase)

Step six: putting in the new joints.

I have always found it easier to put the new joint into the outer stub first than put the stub onto the shaft rather than putting the joint on the shaft and trying to add the stub after.

Reassembly is VERY close to the same as dissasembly. Remember that we had to remove both caps before we can take the cross out? Well, we need to put the cross in before we can put the caps on.
Here you can see the cross sitting in the joint as we get ready to put the caps on.
http://pic40.picturetrail.com/VOL267.../332559702.jpg

At this point, I give the cap on top a few hammer blows to ensure that it is seating in straight, then I flip the shaft over and start the opposite side cap. When placing both caps at the same time its important to make sure that they are going in straight, so use a level surface.

Once you get both the caps in all the way, you can see the C-clip groove. Just install the clips and you are golden.

Step seven: Reassembly

Reassembly is pretty much the reverse of the disasembly process. But we want to take this chance to clean up and use Never-Seeze to keep from having such terrible corrosion problems in the future.

When we look at the knuckle we want to take a wire brush and clean up all of the areas where the hub will meet it. Also we want to clean out as much of the axle tube as we can reach into and ensure no debris gets pushed into the seal area.
http://pic40.picturetrail.com/VOL267.../332559680.jpg

Also we want to clean the edges of the hub where they will meet the knuckle. You will be able to see an outline in the rust to identify where you need to clean.

Once everything is clean, put a THIN coat of never-seeze on. A little goes a long way. You will end up with it all over stuff otherwise. Put a touch of never-seeze on every bolt you put in as you reassemble. You will thank yourself later.

The rest of the reassembly process is straight-forward. If you were able to get it apart, you have all the knowledge to get it back together.
Needed Torque Values:

Axle Hub nut: 175 ft. lbs. to set, recheck 150 ft. lbs.-200 ft.lbs.
Unit Hub to knuckle: 75 ft. lbs. to set, recheck: 70-80 ft. lbs.
Brake Caliper bolts: 30 ft. lbs. to set, recheck: 25-35 ft. lbs.