Rear bearing replacement with pics (1 Viewer)

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BMThiker

I aim to misbehave
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At just over 200K on the odo, I suspected it was time to replace the rear bearings. I've been checking them periodically at the gas pump by putting my hand on the center of the hub to gauge relative temperature. The passenger side has been feeling a bit warmer than usual and it's been around 90-100K since I last changed it. So I decided to go ahead and take care of this before my trip to Hot Springs in a couple weeks. If the bearing fails, it's not the kind of thing you can easily fix on the side of the road or even in an average garage for that matter. Also, if it fails catastrophically, it could damage your wheel speed sensor.

This job requires special tools and at least a 20T hydraulic press, both of which I had access to. You could fabricate your own tool used for separating the shaft from the hub assembly, but that is another project for another discussion. From the pictures below you'll see that it's a fairly simple approach, but would require some careful fabrication.

For starters, I'll say that I already had spare axle shaft assemblies that came from a parted out FJC. This at least allowed me to work on my replacements without being decommissioned. For that reason, the steps may be non-linear for those that are going to attempt this job on their "live" axles. I am starting with the axles already on the bench with the wheel sensor already removed.

Step 1, remove the circle-clip.
RearBearing (1).JPG


Step 2, assembly of the "special service tool". The mounting plate on this tool is reversible so that it can be used on each side. Line the plate up with the bolt pattern on the hub face and then mount the plate to the shaft section of the tool. Then the tool gets mounted to the axle...
RearBearing (2).JPG


Step 3, using the 17mm nuts from the back of the unit bearing, you will bolt the extraction tool to the hub face. The idea is to set the tool in the bridge of the press so that the axle shaft can be pushed down by the piston, thus separating the retaining ring and bearings from the hub base.
RearBearing (3).JPG

RearBearing (4).JPG


Step 4, Now we're ready for the press. That retaining ring is a real monster and I would recommend that you proceed with much caution during this process. The retaining ring is not a reusable part, but because of its location/position it is really hard to get a cutoff tool in there to assist in this process. I doubt that even penetrating oil would make a difference here.

But, alas, it did break free. As you will note there is still the outer bearing race attached to the axle shaft. Everything in the lower half of this picture can be tossed into the recycling bin. (save the ball bearings for your slingshot pouch)
RearBearing (5).JPG


Next up, shattering a race...
 
nice work... for those who don't have a press... you can take the axle to a local machine shop and they'll pull the old bearing and press in the new one making this a bit more DIY for average garage guys. Of course then you don't have a reason to buy a press, so you might want to ignore that advice :)
 
Let me back up to the last photo. Once the shaft is cleared on the press, the hub unit itself is still lightly pressed into the dust shield for the rotor. Some light tapping with a mallet should break it free as pictured in the bottom right above. The 4 lugs should stay in the dust shield piece.

Step 5, cracking the race on the axle shaft. Here's where a cutoff wheel comes in handy. Make several slices into the race. Be careful not to cut into the shaft itself, but get as close as you can and cut as deep as you can with the disc you have. I suggest wearing long sleeves and a full face mask for this task. The race material is very brittle and little pieces (shards) tend to fly in the tangent of the cutoff wheel. Once you made the cuts (and before you toss the face mask to the side) hit your cuts with a cold chisel and small sledge hammer. It shouldn't take more than a few whacks to crack the race clean through - they really are that hard/brittle.
RearBearing (6).JPG


Step 6, set the new unit bearing into the dust shield bracket and firmly run the 17mm nuts down on the lugs so that they fully seat.
It should look like this from each side.
RearBearing (7).JPG

RearBearing (8).JPG



Step 7, now it's time to press the unit bearing assembly onto the shaft. It's a good time to take some steel wool to the shaft to smooth out any pitting where the old bearing and retaining ring were. The dust shield on the end of the axle shaft will have accumulated a fair amount of grime, so take it to the parts washer and give it a good scrub so you don't get any excess dust inside the bearings.

Taking a steel tube that matches the diameter of the bearing face and is longer than the axle shaft, you will press the assembly into place. Keep in mind that the outer ring of the bearing face is the magnetic tone ring, so choose a tube that is smaller than the tone ring diameter but bigger than the axle shaft diameter. Here's my setup right before it goes in the press.
RearBearing (9).JPG


Since the 6 wheel lug studs are vulnerable here, make sure you support the hub from the center and edges. You do not want to press your six lugs out while attempting to press the unit bearing assembly in place. And, if any of your wheel lug nuts look buggered up, now is the time to replace them. They are not impossible to service once the unit bearing is fully seated, but certainly easier.

RearBearing (10).JPG
 
The last step is seating the bearing retainer ring over the axle shaft. It is just a repeat of the last step, but your press may groan a bit more and you may wince a little with each bump of the press. Again, it would be prudent to find that full face shield and wear it as you monitor the progress of the press. There is a slightly domed washer that goes under the retainer ring and I think its purpose is to provide a set preload when the retainer ring is in position. You'll know the position because it will have just cleared the cutout for the circle clip. Once you get the circle clip in place you are done. All that's left is returning the axle to the axle housing. I suggest you replace the oil seal on the end of the axle housing tube as well.

RearBearing (11).JPG
RearBearing (12).JPG
 
like your press tool, good idea to make it "reversable" for both sides
ended up just bringing one to local dealer to have it done when i helped a friend
 
@BMThiker, besides the heat on the hubs did you notice any other signs of wear (bearing howl etc)?
How were the bearings that you pulled out?

With the amount on our ODO you've now got me wondering if we should be looking at doing the same.
There was some heat buildup on one side (slight, certainly not hot) but i found a caliper guide pin that was
bunged up so i did the back brakes last week.
We haven't taken the truck for a good run yet to see if that's were the heat was being generated from (though i suspect it is).
 
@BMThiker, besides the heat on the hubs did you notice any other signs of wear (bearing howl etc)?
How were the bearings that you pulled out?

With the amount on our ODO you've now got me wondering if we should be looking at doing the same.
There was some heat buildup on one side (slight, certainly not hot) but i found a caliper guide pin that was
bunged up so i did the back brakes last week.
We haven't taken the truck for a good run yet to see if that's were the heat was being generated from (though i suspect it is).
@NorthFJ
Man, I'm sorry I didn't see this followup query until now. I was digging through some old threads in this section and just now noticed your question.

As I mentioned the hub was getting slightly warmer than normal, but no other obvious sign of wear were present - no noise or vibration or leaking. The unit bearings definitely looked used, but not horrible. It just seemed like it was time to do it.

On my first set of axles bearings (original factory installed), one did actually fail on my way to the garage. I think my ODO was about 95K at that time. I was planning on doing something else that day at the garage, but when I arrived the rear right tire was covered in 90Wt and it was good that I only went about 4 miles in that condition. I had no other warning that the bearing was failing, just the sudden leaking. This seemed unusual since I've replaced noisy front bearings that gave plenty of warning. So I guess the safe thing to do is shoot for replacement every 80-100K, depending on driving conditions (lots of water crossings will eat bearings quicker).
 
@NorthFJ
Man, I'm sorry I didn't see this followup query until now. I was digging through some old threads in this section and just now noticed your question.

As I mentioned the hub was getting slightly warmer than normal, but no other obvious sign of wear were present - no noise or vibration or leaking. The unit bearings definitely looked used, but not horrible. It just seemed like it was time to do it.

On my first set of axles bearings (original factory installed), one did actually fail on my way to the garage. I think my ODO was about 95K at that time. I was planning on doing something else that day at the garage, but when I arrived the rear right tire was covered in 90Wt and it was good that I only went about 4 miles in that condition. I had no other warning that the bearing was failing, just the sudden leaking. This seemed unusual since I've replaced noisy front bearings that gave plenty of warning. So I guess the safe thing to do is shoot for replacement every 80-100K, depending on driving conditions (lots of water crossings will eat bearings quicker).

No worries at all.....looks like i better get onto replacing ours given the mileage! Thanks again for the great write-up, it's very well done!
 
Going to be diving back into these again soon. I picked up a new tool which looks beefier than the first scratch-made SST I used to do this project. A few months ago @pappy linked a video to a guy on YT and I bookmarked it. While that video was for an older 4R with the tone ring, the process is pretty much the same. The guy in the video was promoting another guy on E-Bay for his bearing tool. I saw how the tool kit made the entire job a bit easier with special plates and perfectly sized tube pressing tools. [Last time around I was scrounging the shop for tube cut-offs and the pieces.]

The E-Bay seller has several versions of the tool, and I got the kit that is universal across several Toyota model trucks. Will post results soon.
1617640068990.png
 
That tool made the job easy.
 

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