Rear Wheel Bearing Replacement – Jeep Cherokee Dana 35
Janice’s 1999 Jeep Cherokee has had a roar in the rear axel for a while now. I finally got around to checking on last week.
I ordered new bearings and seals from Crown Automotive. Since her rear differential is the Jeep Trac Loc, I had to have the friction modifier compound for the grease. I found that at Advance Auto.
I began by lifting the Jeep and removing the rear wheels and brake drums. These had never been off and still had the little clips from the assembly line on two of the lugs. I cut those off with dikes.
Next I let Janice remove the cover. Janice dropped it in the bucket of grease that made quite a mess.
Next I used a 1/4 inch 12 point box end wrench to remove the bolt from the cross pin. I had been concerned that pulling the axles on a Trac Loc diff would be more difficult but it was exactly the same as any other stock Jeep Carrier. I just removed the pin and slipped in the axle to release the C clip.
I removed the left side axle first as it seemed the noisiest. I had a little trouble getting the seal out because the brake shoes were in the way of getting a chisel in like I wanted to. But using a combination of the chisel, vise grips and a seal puller, I eventually popped it out.
I then used an axle bearing puller attachment on my slide hammer to pull the bearing. It takes quite an impact on the slide hammer to get the bearing to move. I have done this job on other Jeeps so I knew to hit it hard. The bearing came out smoothly once it stated to move.
The new bearing seems a very tight fit. I had trouble getting it to start straight in the axle tube. I did not have a bearing driver quite the right size and in trying different ones I somehow damaged the bearing. I noticed some of the rollers missing when I got it in place. So I had to use the slide hammer and pull the new damaged bearing.
I was more careful with the second bearing and got it in with no problem. I put a small amount of Permatex on the outside of the seal and drove it in place. I put a little gear oil on the seal to prelube it.
As I was wiping down the axle shaft to reinstall it, I noticed that there was checking in the bearing race on the shaft. Shaft will have to be replaced. I checked for spares but the only one I had was from a ZJ and the ABS tone ring was different. I replaced the original shaft temporarily.
I slipped it in place and reattached the C clip. I pulled the other shaft and noticed it had some wear as well. I will have to get two replacement shafts along with another bearing to complete the job. I reinstalled the other axle and C clip and coated the cover flange with Black RTV.
After letting the RTV set up for a minute or two, I reinstalled the cover and tightened the bolts in a crisscross manner. Janice refilled the diff with gear oil and the tube of friction modifier.
I later pulled the ZJ axles and looked at how to remove the tone rings. My bearing puller was not long enough to reach. I knew I could use my Dad’s press but I did not want to make the drive to his house.
I did some research on the internet and found a forum post that suggested that the rings would come off easily if heated. Since it was very cold out, I decided it would be a good time to try. The forum post had indicated that the tone ring was aluminum so I was being very careful not to crack it.
I put the axle shaft in the vise and began heating the ring with my acetylene torch. Soon I was able to pry the ring of the seat. I dropped it on the floor to cool. I noticed that it did not sound like aluminum.
I took a magnet to it and found it was indeed magnetic. That made sense to me since the tone ring is used to generate a magnetic field for the sensor to rear the wheel speed. It had to be steel. I was more aggressive with the heat on the second one and it slid off easily without any prying.
These shafts had no visible wear on the bearing races and look like they will make fine replacements. I just have to get more gear oil and another bearing and then find time to do the job again.
UPDATE: I have the spare axle shafts ready to go in but so far the old axles are running quietly. I will just let them run for a while.
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