Clogged diff breather tube blowing axle seal?

[Dieselchessy]

The theory being pressure from heat pushed oil past the 20 year old rubber wiper seals and once you fixed the breather and pressure issue the oil would no longer be pushed past the seals.

I think it more likely that the 20 year old wiper seals are bad, the bearings worn, and probably the collar where the seal rides is worn as well.

 

[mtbtim]

Bit of deferred neglect and maintenance.

Rear axles have both been leaking from both sides, soaked everything (ABS gear), drums, rear shoes, grease on the rims, the whole 9 yards.
Stopped leaking, probably leaked below the level where it will affect the rear axle seals.
Rear diff breather was definitely SHOT, in fact, it crumpled and became two pieces when I took it out with a deep 14mm socket.

Replaced with a new one from Toyota (teflon taped the threads like mtbtim), and filled 1 full quart (didn't start leaking from the fill). I purposely didn't do an extender, cause I'm not sure how much longer I'm keeping the truck., and while I never cleaned out the mess from the first round of leaks, looks like it has stopped leaking. I also didn't fill up until it leaks, because if it's going to leak, I'd rather it be half a quart than say 1.5 full quarts on my garage. Also, I've had amsoil gear oil sitting for a while that I was going to drain/fill the rear diff with a year ago, but when I opened the fill port back then, very new looking fluid start dripping out. Unknown age, but I did not want to replace such new looking gear oil back then.

With a confirmed non-operational rear diff breather replaced, is it possible for the rear axle seals to reseal properly? OR is it a case of "once they leak, they will have to be replaced"?
For reference: 99 rear locker with just over 120k miles.

It's possible that the seals might still be ok. But, you've admitted that the gear oil has gotten into the brakes which means it got into your axle bearings as well. Over time, the gear oil will wash out the grease from the bearing and now the bearing is relying upon the differential gear oil for proper lubrication.

If your new breather did indeed stop the gear oil getting past the seals, you might be in a situation where your bearings aren't going to be properly lubricated anymore and you will have quite the catastrophic failure if you do a long enough drive to overheat the bearings. I've seen this happen before. A kid ignored his leaking rear axle seals for too long and then drove 3 hours from his place to mine for a party we had for our subscribers. His differential gear oil level must have fallen too low to lubricate the bearing with gear oil and it caused his bearing to overhead and implode. It ended up destroying his axle and luckily he was able to find a replacement axle at a local PickNPull. Unfortunately for me, I had to spend 3 hours of my party fixing his truck.

If you want to spend the least amount of money as possible for this, I'd pull the axles, replace the axle housing seals and then take the axles to a shop that knows how to pull off the ABS tone ring and inner retainer without cutting them off and then have them press them back onto the axle for you with the inner retainer flipped (bevel facing the tone ring) and have approximately 4-5mm of polished axle showing above the retainer. This will put the seal lip close to dead center onto the inner retainer. I would also take a small screwdriver or similar tool and pry up the bearing seal cover, clean it out with some brake cleaner and then re-pack it with a good hi-temp bearing grease. Lastly, I'd clean up the brakes really good and get all the gear oil out of there. You really should replace the shoes because they will have absorbed gear oil, but cleaning them off with brake fluid is better than nothing and it will only cost you the cost of a can of brake cleaner.

Here's our Rear Axle Seal Replacement video so you'll understand the job really well:

<iframe width="560" height="315" src="https://www.youtube.com/embed/AVhSDnw2ugo" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>


If you wanted to replace the brake shoes, you could use this video:

<iframe width="560" height="315" src="https://www.youtube.com/embed/IJkVEBYSecs" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

 

[Brian.]

The theory being pressure from heat pushed oil past the 20 year old rubber wiper seals and once you fixed the breather and pressure issue the oil would no longer be pushed past the seals.

I think it more likely that the 20 year old wiper seals are bad, the bearings worn, and probably the collar where the seal rides is worn as well.

There's a Little more to the theory...

Once the oil is pushed past the seals, it washes the grease from the bearings which causes increased wear and leads, directly, to seal failure.

Generally speaking, if so much oil came past the seals that it's all over the brakes and tires, the bearings are on their way out (if not totally gone).

 

[mtbtim]

There's a Little more to the theory...

Once the oil is pushed past the seals, it washes the grease from the bearings which causes increased wear and leads, directly, to seal failure.

Generally speaking, if so much oil came past the seals that it's all over the brakes and tires, the bearings are on their way out (if not totally gone).

I guess you were typing at the same time I was. We both mentioned something similar but I think it's more of a case that since the bearing grease has been mostly washed out, the bearing is relying upon the gear oil for proper lubrication. Lots of bearings are lubricated with gear oil, for example, the bearings in our differentials and transfer cases. As long as the gear oil doesn't fall too low, the bearing will be lubricated and it won't incur excessive wear. It's when the gear oil falls too low to lubricate the bearing that bad things happen.

 

[Dieselchessy]

I was inventing a theory for the supposition that all would be well once the diff breather was fixed.
Sarcasm...

Of course there is no reason to clean up the mess from a failed axle seal without replacing brakes, seals, bearings, ect.. especially on a 20 year old rig.

 

[plcfcng]

I'm with Tim on this one if you know that you have a boat load of miles on your 4runner lets say 150,000 plus and you have a seal failure do yourself a favor and do both the rear axle bearings and seals. If you have a seal failure with only a few thousand miles and just had the bearings replaced you may have had the bearing installer over press the bearing causing a poor seal contact. If you have a seal failure with lets say 30,000 miles on your bearings them maybe a clogged vent. In any case if you replace you bearings or seals be sure to check or replace your vent it's cheap to do either.:gossip:

 

[Kanoe]

Here is a photo to illustrate what the guys have mentioned about the grease.

This is from a very minor axle seal leak. Just a little oil in the ABS cavity, none as far as the brakes. If you are seeing oil in the brakes, consider the bearings to be ruined (or needing repacking if you go that way).

This is the mess I found in mine, there was almost NO grease left inside the bearing.

 

[nissanh]

I did the bearing, seal on driver side yesterday... got the seal to ride on the middle of the retainer.

I find LOTS of youtube "pros" posting videos on how to remove and install the seal/bearing. No one states the importance of installing the inbound retainer correctly so that the oil seal is perfectly centered on the retainer, one said it is to keep the ABS ring in place!. I made a special note on those videos asking viewers to watch TIM's videos.

One has to redo the job again and again until they get the oil seal to ride at the center of the retainer.

On the side note: I contacted Duane, the person invented the axle bearing remover tool and he gave me a generous discount on the adapter plate and I am testing it on a Land Cruiser and need to report back as he wants to see its comparability with cruiser axles.

 

[snydmax]

Think I’m a victim of a botched axle seal job... had all the parts [MENTION=120071]mtbtim[/MENTION] suggests in his vid... bearings, and gears, retainer rings done on both sides a couple months ago and found this on Saturday

At least the passenger side is dry! How long do I have before the new bearings are washed out?

P.s. did the diff breather-mod too so vent is good


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[Kanoe]

Think I’m a victim of a botched axle seal job... had all the parts [MENTION=120071]mtbtim[/MENTION] suggests in his vid... bearings, and gears, retainer rings done on both sides a couple months ago and found this on Saturday

At least the passenger side is dry! How long do I have before the new bearings are washed out?

P.s. did the diff breather-mod too so vent is good


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If you have that much oil in there, the bearing is already compromised. Sorry to tell you. See my pic above, I had a lot less oil than that in mine and the bearings were lacking grease. If they are new bearings maybe you can repack. Others have had luck doing so. My bearings were original so I replaced them.

This issue is a b!tch. Such a headache for people. Once fixed correctly it seems to stay gone at least.

 

[mtbtim]

I did the bearing, seal on driver side yesterday... got the seal to ride on the middle of the retainer.

I find LOTS of youtube "pros" posting videos on how to remove and install the seal/bearing. No one states the importance of installing the inbound retainer correctly so that the oil seal is perfectly centered on the retainer, one said it is to keep the ABS ring in place!. I made a special note on those videos asking viewers to watch TIM's videos.

One has to redo the job again and again until they get the oil seal to ride at the center of the retainer.

On the side note: I contacted Duane, the person invented the axle bearing remover tool and he gave me a generous discount on the adapter plate and I am testing it on a Land Cruiser and need to report back as he wants to see its comparability with cruiser axles.

Duane is a good dude. He said he chatted with you when I brought up you ended up bending one of his ABS tone ring/retainer removers. You're the second person to bend one of them. I also mentioned you were using a Timken retainer rather than OEM and maybe that was the culprit because of it being much harder to remove from the axle shaft. He's changed the tool design a bit and is going to send me one soon to try out. He's making the remover a bit thicker to sustain more force.

It's a bummer but somebody has copied his design and is selling them on Ebay now too. There's like 5 different Ebay sellers offering a tool that looks just like his. I'm guessing he didn't patent this design. That sucks that people have no problem ripping off somebody's idea. I believe in Karma and somebody will shit all over these cork soakers one day. Thanks for helping Duane test out his tools.

 

[snydmax]

If you have that much oil in there, the bearing is already compromised. Sorry to tell you. See my pic above, I had a lot less oil than that in mine and the bearings were lacking grease. If they are new bearings maybe you can repack. Others have had luck doing so. My bearings were original so I replaced them.

This issue is a b!tch. Such a headache for people. Once fixed correctly it seems to stay gone at least.

Sounds like we caught it early enough...visibly the bearing not compromised as yours looked to be... maybe had 3000k since the job.

Now fingers crossed they got the seal right this time. I’ll be checking behind the abs sensor with some major OCD for a while.


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