Leaking axle seal?

[ShadowsPapa]

Fill until just below the fill hole. No different than others from the manuals and Jeep sites I've seen.

From a Jeep site -
The important thing is to make sure the diffs are filled to the correct level, which is just a bit over the bottom of the inside of the axle tube. That's where the OEM covers' fill holes would put it with no lift.

Non-factory covers may mess up the levels if the fill hole isn't in the factory location or if the differential is tipped due to a lift, etc.

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[ZSum73]

Anyone else get a repair done yet?

 

[Rubsal70]

Anyone else get a repair done yet?

I've had mine for a week and no new leaks. Still on my toes though, since a few had problems after their fix. I will let yall know next week again

 

[Axeman]

had leaks that slowed or stopped after leaks began, prior to repair

This is where I'm at. I had a noticeable leak at 200 miles where it would pool in the rim after driving. I went to the dealer at around 400 and it had slowed significantly by then to just seeping. They ordered a replacement axle assembly (axle/seal/bearing) and I am still waiting for it to come in. I'm close to 2k miles and it hasn't even been seeping anymore. I always thought it was overfilled, now I am wondering if I should just leave it alone...

 

[ZSum73]

This is where I'm at. I had a noticeable leak at 200 miles where it would pool in the rim after driving. I went to the dealer at around 400 and it had slowed significantly by then to just seeping. They ordered a replacement axle assembly (axle/seal/bearing) and I am still waiting for it to come in. I'm close to 2k miles and it hasn't even been seeping anymore. I always thought it was overfilled, now I am wondering if I should just leave it alone...

Did you ever check the level to see if it was over filled when it began ? Mine leaks and then doesn't leak, then it starts again, not a lot , but it's splattered a little around the rim pooled in the rim once. Stopped then a tiny bit again not dripping, but on the lower edge of the brake shield. Idk what to do. Dealer looking at it Monday. I'm hesitant about what to do. Where on North Shore? What dealer do you use? I'm on North Shore too, but bought on South Shore because no one had any stock. My other concern is the brake pads being contaminated and breaking down, but I don't want to clean it until it's seen.

 

[Axeman]

Did you ever check the level to see if it was over filled when it began ? Mine leaks and then doesn't leak, then it starts again, not a lot , but it's splattered a little around the rim pooled in the rim once. Stopped then a tiny bit again not dripping, but on the lower edge of the brake shield. Idk what to do. Dealer looking at it Monday. I'm hesitant about what to do. Where on North Shore? What dealer do you use? I'm on North Shore too, but bought on South Shore because no one had any stock. My other concern is the brake pads being contaminated and breaking down, but I don't want to clean it until it's seen.

I took mine to Kelly Jeep in Lynnfield. I'm not sure if I'll be doing much with them after this repair because they don't seem to 'mod friendly'. I had the same issue with inventory, I ended up buying mine down at Imperial in Mendon and I'm not going back down there for service. May try Herb Chambers in Danvers.

 

[ZSum73]

I took mine to Kelly Jeep in Lynnfield. I'm not sure if I'll be doing much with them after this repair because they don't seem to 'mod friendly'. I had the same issue with inventory, I ended up buying mine down at Imperial in Mendon and I'm not going back down there for service. May try Herb Chambers in Danvers.

I bought at Quirk in Braintree. I'm going to go back there just because I had a few things done when I bought mine and they did a great job and I'm so ocd about this truck. I've had issues with Kelly's service manager and they tried to screw me on a warranty claim on my wife's jeep and we bought an extended warranty from them, took it elsewhere and it was covered. Herb Chambers is good but always so busy and they always hassel me because we didn't buy the vehicle there, even though I have in the past. I wish you luck still not sure what I'll do but I'm gonna have them at least look at it and document it.

 

[ShadowsPapa]

This is where I'm at. I had a noticeable leak at 200 miles where it would pool in the rim after driving. I went to the dealer at around 400 and it had slowed significantly by then to just seeping. They ordered a replacement axle assembly (axle/seal/bearing) and I am still waiting for it to come in. I'm close to 2k miles and it hasn't even been seeping anymore. I always thought it was overfilled, now I am wondering if I should just leave it alone...

If the seal is good, if the sealing surface of the axle is good, that axle tube could be 1/4 full of lube and it should not leak. Seals seal against liquids so the "over full" bit isn't a concern unless it's grossly overfilled to the point of pressure. Normally pressure actually helps a lip type seal seal better.
I don't get where the overfilling bit is coming from - non-mechanics or others, I'm sure.
Check the specs, check how axle housings have been filled for decades, to just below the fill opening. You fill until it reaches the bottom. That is no over-full and anything else is internet lore.
Think of engine seals - there's oil against them at all times, even under pressure in some cases - but they don't leak. Transmission seals - same thing, they don't leak.

Think of your LAWN MOWER engine, crank shaft sticking out the bottom, oil in the crankcase SITTING against that seal, literally sitting on top of it - no leaks.

No, over-full is something that got started by non-technical people and has taken on a life of its own with nothing to support it.
Yes, lower the level and suddenly there's no lube out at the end of the axle TO leak - but now it's too low.
It's like saying my upper radiator hose leaks, I'll take some coolant out.

 

[Axeman]

If the seal is good, if the sealing surface of the axle is good, that axle tube could be 1/4 full of lube and it should not leak. Seals seal against liquids so the "over full" bit isn't a concern unless it's grossly overfilled to the point of pressure. Normally pressure actually helps a lip type seal seal better.
I don't get where the overfilling bit is coming from - non-mechanics or others, I'm sure.
Check the specs, check how axle housings have been filled for decades, to just below the fill opening. You fill until it reaches the bottom. That is no over-full and anything else is internet lore.
Think of engine seals - there's oil against them at all times, even under pressure in some cases - but they don't leak. Transmission seals - same thing, they don't leak.

Think of your LAWN MOWER engine, crank shaft sticking out the bottom, oil in the crankcase SITTING against that seal, literally sitting on top of it - no leaks.

No, over-full is something that got started by non-technical people and has taken on a life of its own with nothing to support it.
Yes, lower the level and suddenly there's no lube out at the end of the axle TO leak - but now it's too low.
It's like saying my upper radiator hose leaks, I'll take some coolant out.

Whether this was a case of over-filling or not, it is a possibility. All of the situations you mentioned are all capable of leaking if overfilled. The systems are designed to operate and withstand a certain capacity of fluid to allow for expansion under heat and pressure. Thats why engines have breather valves and oil catch cans.

When systems are overfilled, that expansion finds the weakest link to escape. With the differential breather tube mounted up top of the frame, the axle seals are the weaker of the housing compared to the pinion seal or differential cover gasket.

I will agree that passenger side axle leak is more than a coincidence. It's likely that there is a defect in that assembly, be it the axle, the seal, or the housing itself. Normally once a seal starts to leak, it is unlikely to rectify itself and stop leaking. In my case, the leak has slowed to weeping, and only after extensive drives. The fluid level is filled appropriately at this time. I do have a feeling that it was overfilled from the factory line and has corrected itself to where the capacity is no longer building such pressure to leak as much as it was.

 

[ShadowsPapa]

Whether this was a case of over-filling or not, it is a possibility. All of the situations you mentioned are all capable of leaking if overfilled. The systems are designed to operate and withstand a certain capacity of fluid to allow for expansion under heat and pressure. Thats why engines have breather valves and oil catch cans.

When systems are overfilled, that expansion finds the weakest link to escape. With the differential breather tube mounted up top of the frame, the axle seals are the weaker of the housing compared to the pinion seal or differential cover gasket.

I will agree that passenger side axle leak is more than a coincidence. It's likely that there is a defect in that assembly, be it the axle, the seal, or the housing itself. Normally once a seal starts to leak, it is unlikely to rectify itself and stop leaking. In my case, the leak has slowed to weeping, and only after extensive drives. The fluid level is filled appropriately at this time. I do have a feeling that it was overfilled from the factory line and has corrected itself to where the capacity is no longer building such pressure to leak as much as it was.

>>When systems are overfilled, that expansion finds the weakest link to escape. With the differential breather tube mounted up top of the frame,<<

That's funny., really.
You're trying to feed internet fodder to a long-time tech with factory training.
The vent being up high makes it a more difficult place for pressure to escape than an axle seal - and the pinion seal is stronger?
Really? Take that vent to the roof - NO DIFFERENCE. None, not a bit. All you are doing is making the path to get there longer but the RULE of hydraulics, and in this case ordinary fumes and air, is that regardless of the length of the pipe, the pressure is the same through-out. That means the pressure in the differential housing is exactly the same as the pressure at the end of the vent line even if the vent line is on top of the truck.

That axle seal actually is designed to seal HARDER with pressure against it. It's a tapered lip.
It's a WEDGE and the more force that is applied to the back side, the more it is forced against the axle. Study one a while. Put them in backwards and the pressure forces right out past the seal, put in correctly and pressure SEALS it harder. It's like a hydraulic piston - the pressure on the inside wants to move the seal lip out, it can't because it's like a door stop wedge - the harder you push the tighter it seals (to a point)

You really missed the boat on the crankshaft seal example for the lawn mower because oil SITS on the seal at all times. OIL SITS ON IT. So how is 4 more ounces - making it over-filled, going to make it leak out that seal - which unless WORN actually seals harder because it's a wedge shape?
I started with small engines in the early 70s and worked up to cars by the mid-70s.
There's oil against those seals. You can add more oil to that lawn mower engine and that seal STILL will not leak because it already had a couple of inches of oil sitting right on top of it. Same for the car engine - there's oil against the back side at all times. The problem is when non-mechanics toss theories out there that fly against reality. You have not proven a thing, not demonstrated why. (in a true debate, you can't say "because I said so"- explain how a seal works)

Oil catch cans? Not normally unless added for other reasons. Most engines don't have them. They are for special purposes and never needed in most ordinary cases. And they have NO impact on SEALS.

Breathers? - wrong reasoning. And they aren't open breathers in any case. You want a VACUUM in the crankcase not for seals per se but to increase the difference in pressure above and below the rings for ring sealing. Why do racers eliminate the PCV and then put in a vacuum pump? Not for the seals. (although it helps)
I've seen cars with plugged PCV valves and crazy blow-by NOT LEAK A BIT by any seals. I've rebuilt some of those engines and the seals were still dry (but the air filter housing filled with oil)

Explain how the axle seals are weaker than a pinion seal? You know that many differential housings have "funnels" and channels built into them to DIRECT lube to the pinion bearings, right? So they are BATHED with oil against them at all times. Pull that pinion seal and lube will - or should - run out. Yet that seal being of the exact same design and type does not leak.
So point out exactly - how is that axle seal a weaker link than a vent.
Explain how the axle seal is a weaker link that the constantly bathed pinion seal that is the EXACT SAME DESIGN. Pull a pinion seal out and lube should also hit the floor.

Expansion of the air pressure in there is vented out the vent - if the seal can't take 3 or 4 or 5 psi then it's totally faulty, period. All of the seals, pinion, left axle, right axle, are the same exact design. The vent no matter WHERE it is, is far far more open than any tapered lip type seal.

The problem with me using logic and design facts against the internet is that there's no end to the speculation and junk floating around out there, but there's only so much logic to toss out.
I spent a college semester on design - drive trains, engines and yes, seals.
Not sure where you got your info - but likely a forum.

It's totally wrong.
And if I am wrong, then college books, engine design books, and repair books for many decades are also dead wrong.

 

[ShadowsPapa]

I did an experiment - I used my laser level to strike a level line from axle tube bottom to axle tube bottom left to right, across the fact of the differential cover. I made the line just a shade high of the bottom of the outside of the tube to allow for tube wall thickness, so my line should be close to the level of the inside of the axle tube in the differential housing.
That line went across the fill plug.
I ran a string along the laser line so I could more easily photograph it.
The string ran along the bottom of the fill plug hole.
So if you pull the plug out and lube runs out, it's too full, we know that, it's ALWAYS been that way since the beginning of automotive differentials.
But if the lube is not above the bottom of that fill hole, it's not into the axle tubes.
So anyone thinking their differential is over-filled, pull that plug. Ideally you'd be about 1/2" below that.
I don't get the speculation - if you are concerned pull the DAMNED PLUG! Stick your PINKY finger in the hole and reach down, don't insert your finger past the first joint at the end.

Now to another point - to over-fill these means that they'd have to be tipped, or, the system filling these didn't read the book LOL. There's a capacity and these days, they squirt in the amount the designers called for automatically, not someone sitting with bottles sitting next to them filling the housings as they pass by on a conveyor belt.
Even your milk bottle is filled by machine. Your dealer doesn't dump quart bottles of oil into your engine. Ya think the factory does?

Anyway, if there's so bloody much concern, why aren't people laying under their truck and pulling that plug and checking? If it's a bit below the hole that's perfect. If it runs out, let it. then when it stops put the plug back in.

Too many shade-trees and novices and non-mechanic speculating out there. in 3 minutes you can tell if it's "over filled" and if it is, then there's a problem at the factory with their automated equipment. But then explain to me why ALWAYS the right axle, NEVER the left and never the pinion? Hmm? Explain - and not "I think that" or "I read that". If you read it, link to it.

 

[gpwrang33]

So, I'm not saying they are overfilled or underfilled but how do the fill them during production? You would probably only know if you were actually at the plant during production but do they fill them on a rack to hold them at the proper installation angle? Or is it with the case pointing down? Do they fill them by eyesight when it starts to overflow its filled? Or do the say it requires "x" amount and put that much in? Could "x" amount be just a little too much? Everything is just speculation at this time until the real reason comes out but that probably will never surface for us to no.

 

[ShadowsPapa]

So, I'm not saying they are overfilled or underfilled but how do the fill them during production? You would probably only know if you were actually at the plant during production but do they fill them on a rack to hold them at the proper installation angle? Or is it with the case pointing down? Do they fill them by eyesight when it starts to overflow its filled? Or do the say it requires "x" amount and put that much in? Could "x" amount be just a little too much? Everything is just speculation at this time until the real reason comes out but that probably will never surface for us to no.

The machine is set to fill to X.Y pints. It's like most production these days - no one fills by eye or by hand any more and haven't for a long time. Even when I toured the Ford and Chrysler plants years ago, and later the John Deere engine plant - no one fills by just pumping until it's full. It's dispensed until the measure is reached and then stopped and then the next one.

This is exactly how I PERSONALLY saw it when I toured - I found another fellow who saw the SAME THING - this is a quote I found about factory filling -
They use an auto fill system, guy filling the diffs just puts a nozzle in, it puts in the measured amount

So - look in the book - that's what they are going to have that auto-fill machine set to.
They could be hanging from the roof of the Sears Tower - pinion pointing down, won't matter. When the machine stops putting out, the next one comes along and gets filled.
They don't have people measuring by cup or by look or by feel - it's metered by machine and has been since before AMC was raped and pillaged by Lee.

It's all automated and has been for YEARS, DECADES even. It's machine. And if it's like my father described, at the end what they've produced in parts vs. what should be used in lube had better match or someone has some 'splaining to do.
Even in my father's UAW factory days - things were computerized.
It was said that due to the close money issues with AMC that the head watched things very closely- numbers off, you'd better have an explanation. Even saw an article about that on a wall in a museum how closely things were watched.

 

[ZSum73]

Whether this was a case of over-filling or not, it is a possibility. All of the situations you mentioned are all capable of leaking if overfilled. The systems are designed to operate and withstand a certain capacity of fluid to allow for expansion under heat and pressure. Thats why engines have breather valves and oil catch cans.

When systems are overfilled, that expansion finds the weakest link to escape. With the differential breather tube mounted up top of the frame, the axle seals are the weaker of the housing compared to the pinion seal or differential cover gasket.

I will agree that passenger side axle leak is more than a coincidence. It's likely that there is a defect in that assembly, be it the axle, the seal, or the housing itself. Normally once a seal starts to leak, it is unlikely to rectify itself and stop leaking. In my case, the leak has slowed to weeping, and only after extensive drives. The fluid level is filled appropriately at this time. I do have a feeling that it was overfilled from the factory line and has corrected itself to where the capacity is no longer building such pressure to leak as much as it was.

Took a long drive to Maine today. Got out took a look and no leak......until I returned from walking the shops and having lunch in Kittery that is...checked again and dripping with a small pooling of fluid in the back of the wheel......

 

[gpwrang33]

The machine is set to fill to X.Y pints. It's like most production these days - no one fills by eye or by hand any more and haven't for a long time. Even when I toured the Ford and Chrysler plants years ago, and later the John Deere engine plant - no one fills by just pumping until it's full. It's dispensed until the measure is reached and then stopped and then the next one.

This is exactly how I PERSONALLY saw it when I toured - I found another fellow who saw the SAME THING - this is a quote I found about factory filling -
They use an auto fill system, guy filling the diffs just puts a nozzle in, it puts in the measured amount

So - look in the book - that's what they are going to have that auto-fill machine set to.
They could be hanging from the roof of the Sears Tower - pinion pointing down, won't matter. When the machine stops putting out, the next one comes along and gets filled.
They don't have people measuring by cup or by look or by feel - it's metered by machine and has been since before AMC was raped and pillaged by Lee.

It's all automated and has been for YEARS, DECADES even. It's machine. And if it's like my father described, at the end what they've produced in parts vs. what should be used in lube had better match or someone has some 'splaining to do.
Even in my father's UAW factory days - things were computerized.
It was said that due to the close money issues with AMC that the head watched things very closely- numbers off, you'd better have an explanation. Even saw an article about that on a wall in a museum how closely things were watched.

So you are saying machines are always right? Or every single assembly that moves down the line gets the same amount? They don't run any other axles on that line? "X" amount couldn't be off by a little bit more than what the book says? Weren't there some assemblies with no lube sent out? Or was that the driveshaft support bearing with no grease? A lot of what about this or what about that. I understand you have a mechanical background but you aren't the only one that knows automobiles and what you say isn't the say all be all. You weren't there on the line when these assemblies were built so you really can't say it wasn't overfilled. It could be multiple of issues that lined up for the perfect storm. Who knows and again I'm sure we'll never know the true answer.

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