Potomacduck

A month ago I wanted to replace the rear brakes on my '99 limited. As soon as I removed the drums, it was obvious, the rear axle seals had leaked and turned the rear brakes into an oily mess. So, being that my runner has 293,000 miles on it, I decided it was time to replace everything from the axle seal out including the rear bearings.

Here are some things I learned:

If your runner has ABS, it can be a big job. You must replace two retaining rings and the ABS skid control Ring to get to the rear wheel bearing. These are pressed on the axle. This is a pain in the butt if you don't have a press, fortunately my friend has a 20 ton press and a gear puller which makes the job as easy as assembling Tinker-Toys.

Also, to remove and replace the retaining ring, ABS ring and wheel bearing you need a Toyota Special Service Tool which fits over the axle and bolts to the bearing cup...............and it costs between $250-300 depending on where you buy the Tool. But if you are cheap like me, you realize that the Toyota Special Service tool is a lot like a 4Runner rear axle. (makes sense right?)

So I went to a junkyard and pulled a rear end off a derelict 4Runner ($20) and after an hour or so with a 4" grinder I had my $20 "special service tool."

After that the job is fairly straightforward. The one oddity we discovered is how the oil seal itself sits in the rear axle.

I've heard of several failed oil seal jobs and now I know why.

We did what most mechaincs do; we tapped in the oil seal into the axle until it stopped. Sounds reasonable, right?

But after that we put some grease on the seal, and re-inserted the axle to determine where the oil seal was riding on the retaining ring, guess what? The new oil seal was riding maybe 2-3 millimeters on the retaining ring - clearly this job was going to leak within a few thousand miles.

So, I went to the other side of the axle and measured the depth of the oil seal with a a micrometer - guess what? The oil seal IS NOT seated at the back stop point of the axle, in fact the factory installed the oil seal a few thous' outside where the oil seal seats if you simply tap it in all the way, you've gone too far and your oil seal isn't sitting where it ought to sit.......at least on ABS axles.

Interesting huh?

So with the new oil seal installed where the factory installed it, all that was left to do was bolt it back together and re-install the rear brakes after turning and cleaning up the drums..............oh, with a nice new coat of flat black paint just to make 'em look good.

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sebastianholmes

J2F42C

+1 on the pics.

Hopefully the link I attached helped with the brakes, and the drums were not rusted on the plate.

On another leaking axle someone posted the same observance, where the the inner seal is not pressed right up against the axle housing itself. I left a small gap (about a .060mm gap I think) when I did mine and it has been good for 13,000 miles so far.

I'd love to have the room for a press. Not happening this year.

Potomacduck

Wish I had taken pics of the job, but we were trying to get finished fast.

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Potomacduck

Update: 9,000 miles later (302,000) the rear axle job and the seals are working perfectly.

Thanks Yotatech.

DRCOFFEE

I'm going to retract my original message in this thread. This topic is dead on. After my seals leaked again in 300 miles I searched and found another member who corborates this idea. mr schuster posted this back in 2008

"Its been a while since I worked at the dealer, but when I was there we replaced axle seals on almost every Sequoia and 4runner in our area. The inner seal would leak and the rear shoes would become saturated in gear oil. Worst I have seen was a locked up wheel because of the brakes swelling up due to saturated linings. Finally Tech support started helping us out a little by asking us not to install new seals flush against the inner axle housing. We were told the seal itself was not at fault, but the metal ring which resides behind the ABS ring was not properly placed on the axle itself. Engineering flaw. The outer ring on the axle is what the seal rides against. We would apply a light coat of white lithum grease to the axle ring and reinstall the axle into the housing then spin the axle one or two times. Then carefully removing the axle you could see where the seal had been riding on the axle ring, if at all. We would take a measurement with a dial caliper of where the seal was originally and where it needed to be. Removed the old seal and replaced the new one further forward from the old seal by the measurment taken. Sounds like a pain and it was, hopefully they have modified the seal to correct the problem, but if not try to do this if your truck is out of warranty."

Rear axel seal is leaking... 3rd gen 4runner

I will redo mine this weekend and set them 2-3mm outside the pocket. I hope this fixes the problem.

Here is a picture showing where the seal was actually riding after 2 weeks and a slight leak again. The polished ring next to the bevel is just on the shoulder and any bumping around was letting lube get by. I am a believer. I set my new seals 2mm out from the pocket bottom. Another point of reference is to flush it up with the inboard side of the ABS sensor hole. Using the grease method to re-test the actual depth of the new seal, put it right in the middle of the spacer.



Here's how I seated the seal to just the right depth equally all the way around. I cut a block of wood (2x3) with a power miter saw to the exact depth and attached it to a bigger board. The top of the T will stop at the housing mouth.

DRCOFFEE

deleted

R.Kipling

I've just discovered that my '99 4Runner rear seals are leaking onto my brakes. I'm not ready to take out a second mortgage to get it done right now. Is there a gear oil that has some type of sealer in it that can get me a few K more miles?

The Runner has been good to me, up to this year. In the last year I had a trans cool line separate from the radiator, both components of the A/C replaced, the exhaust and front brakes/rotors and now this.

Any help and/or suggestions will be greatly appreciated.

THX,
Kip

DRCOFFEE

Its been a month and the seal is still dry.

EDIT: Cinco de Mayo

I spoke too soon. The simple fact is, my retainer just is not making contact with the seal properly. Yesterday I took drastic action. I cut off the retainers and had new ones pressed on. This time I had them put on backwards to put the bevel on the outside giving me more room for the seal to seat against. In the process I had them moved 1mm more inboard. These two changes gives me an extra 4mm of reach inside the axle housing. Plus now I can seat the OEM seal all the way back into the housing where it is square and seals correctly. I checked this morning and there's no sign of leaking. fingers crossed.

to cut off the retainer, I used a dremel with a reinforced cutting disc. Go almost all the way through then hit the cut line with a cold chissel to break it open.

*With the bevel inboard, you cannot move the retainer in more than 3mm without rubbing the axle housing.

Here's a couple of pictures to make it easy to understand.

old configuration


new configuration



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