Rear Axle Seal

Dang rear axle seal failed on the driver's side. Noticed a grease puddle when I parked. Inside of wheel & tire soaked. Popped off the hub... everything soaked, gonna get new shoes.
I'll rip into it on Saturday.
This bums me out because I replaced both rear wheel bearings less than a year ago. Not sure if I got a bad seal last time or somehow screwed up the install. I suspect defective seal, of course.
Looking for a part number for that seal so I can source one before Saturday. Thanky!

 

Outer axle seal (K seal) that goes onto the axle shaft is 90313-54001. I had a machine shop press this in with new bearings etc.

Inner axle seal (S seal) that pops into the axle assembly is 90310-50006. They're cheap enough that I'd get extra in case you have a hard time getting it in like I did. I used an oil filter to get it in.

 

Gear oil is also not good for the bearing grease. If the driver's bearing has gear oil on it, I would get that replaced too.

Also have you done a breather re-location yet? The seal may have blown because the breather was clogged, causing the hot oil to take the path of least resistance - the driver's seal.

 

Thank you! I also had to bring my axle assemblies to a shop when I replaced the bearings. I'm really, really, really hoping that it's just the outer seal so I don't have to pay for that again. He's the only guy in town who has that Toyota specific press die.

 

Man, I just hate to have to replace those bearings again... trying really hard to avoid that, they're frickin new, like less than 5K miles.
I need to know more about the breather relocation, new to me.

 

Yep it sucks, I definitely don't want to have to do this job again. My driver's bearing failed majorly and I suspect the blown seal and gear oil was the main culprit. The machine shop didn't get the outer seal exactly flush against the housing, even after I took it back to them so unfortunately I'm going to have to keep an eye on that.

This is a good write-up on relocating the breather. ARB sells a fancy kit but this method is cheaper. https://www.tundras.com/threads/diy-rear-differential-breather-mod.5253/

 

Thank you again! I was able to source both seals and another bearing up here. I'm gonna suck it up and replace it all again on the driver's side. Sonofabeaver.

 

Quick update on this. Took her apart today and cleaned everything up. des2mtn: I can't thank you enough. My breather was definitely plugged and I'm going to modify it tomorrow for sure. I'm going to need to bring the axle into a shop up here again to press out the old and in the new. Probably gonna be a few days before he can get to it though. Existing bearing feels to be in great condition but replacing it anyway (contaminated), new brake shoes, inner & outer seals, along with new ABS ring. That's the plan.
2021-01-31_04-41-18 by GhostCreekMine, on Flickr

2021-01-31_04-41-33 by GhostCreekMine, on Flickr

 

Very glad this is working out for you - it seems like the stock breather can get plugged way too easily. I know I couldn't blow air through mine when I took it off.

I believe that O-ring on your axle housing is supposed to be replaced too, it's only a few bucks. 90301-88077

 

I appreciate the advice but I'm ok on that O-ring, I wiped it off and put it back on for safe keeping. It's still new, I did a wheel bearing replacement on this a couple of months ago. I ordered the breather parts from Amazon (as per the thread you linked). They should be here this week. I cleaned up the old breather and got it to function but won't be using it... ordered a new one to fit the 3/8" hose extension. Man, that thing was crusty!

 

Be sure that the inboard “retaining ring” that mates with the oil seal and the ABS tone wheel don’t get pressed all the way onto the axle shaft, or you’ll have a leak. There is a specific distance, and it’s NOT until they bottom against the snap ring. I suspect this may be why your seal leaked again after your recent seal / bearing replacement. I made this exact mistake the first one I did.

 

Thank you for that heads-up. I don't think that was the cause of the leak... it would have likely leaked before 5K miles of driving if that were the case. The press guy here is really familiar with the gen 1 Tundra axles and he did a good job with the press tool last time, but I will mention it to him when I drop it off. All clues point to clogged breather. The day it happened I crossed a high mtn pass twice (about 11-12K elev) and I wasn't shy on the skinny pedal. That rapid elevation/pressure change was likely the catalyst causing her to blow out the seals on that side due to my stuffed breather.

 

Yup, probably just the breather then. The one I “oopsed” on took a while to show a leak again, the lip seals on the greased bearing slows the oil leakage down, so I could believe it “lasting” 5K. But if both bases are covered than you shouldn’t need to worry about the 3rd time. ​

 

Is that from when it was pressed too far on? Because that's how it looks to me.

 

No. This was a quick grease test and axle insert without a full bolt up. Saw that it was close and felt good about it. If you look closer you can see the original seal(s) wear mark on the ring. These are the third seals (in 20 years). This axle was a Seal Replacement Job only. Did the Grease Test for grins and took pics to help others envision the Mojo.

Knew the Seals needed replacing by removing and looking down into the ABS Plug with the wheel off. Saw a little oil and did the math on the last replacements (7 years) and performed the repair. Toyota Seals ONLY for anyone doing this. Do not use anything but TOYOTA SEALS!

 

When only the best will do.

 

Follow-up:
Cleaned up all gear oil from every stinkin part and re-installed the rear axle along with new shoes on that side. New seals, tone ring, bearing... everything. Old bearing was 100% fine but I heeded the advice given earlier in this thread and replaced it anyway (contaminated with gear oil).
Also did the breather mod. Simple and effective. I bought the Toyota-specific threaded fitting and a Dorman breather cap... both from A-zon and cheap. Routing the hose was easy. I'm fairly certain that the clogged breather was the culprit. She's sealed now, no leaks. Need to put some miles on it and keep monitoring.
Thank you guys for the excellent advice, very much appreciated.
2021-02-16_10-20-31 by GhostCreekMine, on Flickr

2021-02-16_10-20-52 by GhostCreekMine, on Flickr