Rear wheel leaking oil - third time

11178adm wrote:
without getting too far out in the weeds explaining a unitized seal, a conventional lip type seal is installed in the hub and the seal lip rides on and rotates on the seal surface of the load housing. a unitized seal comes assembled with two separate unconnected parts, it is installed in the hub the same as a conventional seal, the inner diameter is a tight fit on the load housing and does not rotate with the hub, the seal surface and rotation is internal in the seal. if the seal is installed with the proper tools and the bearings set to the proper end play a leak usually caused by damage to the hub or the contact surface on the load housing. hope this helps

Thanks, this will give me some imputs for my original installer.

slickest1 wrote:

Kidoo wrote:

crasster wrote:
I'm curious how much oil it is leaking? A gush, small puddle, or just a couple of drops? It can matter when diagnosing over text. :)

At first, it was making a small puddle when I stopped, maybe one inch by two inch. Now, it seen to have slowed down to a line then it stop. I did had oil it and tilted the axle on both side and drove around.

I don't quite understand what you mean by tilting the axle and having oil at each end. Are you sure you are not over filling the diff. with oil? It is full when it runs out the plug on the side where you fill it.

Another cause for wheel seals can be overheating brakes, I don't know if that applies or not. Clogged vent tube as well.
Like said above it may be a problem with the hub if it is the same one that keeps failing.

I did not overfill the hub, the oil is barely equal to the hole. I also checked the vent, this is a vent the size of a pencil, and it is not blocked. I tilt the axle to make sure there is oil at the end of the axle, I saw this on a PDF from Eaton Axle, I do not know how they fill up, so I just want to make sure their is oil in there before I get going again as I am on the road right now and do not want to spend another 400 dollars on this. It actually stops leaking after a while sitting, so I figure it could be because it drained all of it's oil, just like it does when you remove the hub, it leaks empty, then it stop leaking.

The brakes are not overheating, I have a TPMS that tells me the temperature of the wheels and it never exceeded 110 F.

FIRE UP wrote:
Kidoo,
This is not all that complicated. You don't say what chassis you have. I'm not all that familiar with Monaco and or, any chassis's they may use, if they're not Freightliner. I replaced my left rear hub seal about 4 years ago or so and it's been fine ever since. Not bragging, not at all. Just saying that it's a simple job and, if yours continues to leak or, at least starts leaking after a repair, obviously something's got an issue.

The seal, normally is installed in the rear of the hub. And, it seals on the axle housing, not the axle itself. I'm not sure what 11178adm was talking about in terms of a "Unitized" seal. And, also not sure what he meant by the statement that it (the seal) "does not rotate". If it's like mine, it HAS TO ROTATE, based on the fact that it's installed in the rear of the hub, and the hub rotates.

Now, I'm presuming that yours is like mine. If it's different, as in a total different design, then all bets are off. But it you take a look at the pics below, you'll see what I'm talking about. In the pics, you'll see the main hub, bearings, removed (bent seal) hub retaining nuts and locking/clocking retaining spacer. The hub it sitting on my table, with the wheel studs facing down. What you see as a silver tooth ring on the back side of that hub is the ABS rotator ring. The seal, fits and is installed, just inside the hub, just inside that ABS ring.

The rear or, inside bearing is installed, then the seal is pressed into position. It's that simple. But, if you're having the trouble with sealing you are, There's some checks that may be in order.
1. Pre-check the seal to axle housing surface with the new seal. Make sure it's a semi-tight fit.

2. Make sure there is no deep grooves from the older seals that were in place before. Even though seals are made of soft material like rubber, neoprene, viton and other substances, it's amazing that sometimes, they will wear in a groove on the housing that they ride on, causing a potential loose fit which can cause a leaking situation.
3. Make sure the seal fits snugly in the hubs housing.
4. The seal, again if it's similar to mine, needs to be installed with great care. That is, it must be installed either with a specific seal installation tool or, at least if the tool is home made, it must be in contact with the entire circumference of the seal-back, as the seal is being either driven in or, pressed in.

If a seal of that size is "hammered" in, in a rotational method, that is if it's pounded in a little at a time, as you pound around the entire seal-back, it's highly possible to warp and or distort that OUTER sealing surface of the seal, the part that seals against the hub, not the rubber side that seals against the axle housing. If it gets warped or distorted, it's possible that, that's where your leak is emanating from.

I have the pictures you see below. But, I do not have a picture of the exact surface your seal rides on, the axle housing itself, in Photobucket, where I store on line photos. Again, if this situation is not like yours, then all this is worthless to you. Good luck.
Scott

Thanks for all this info, really appreciate. I will have to wait to be home, but I will certainly give it a try. My chassis is a Roadmaster, I guess the Axle is Layton, GM or Ford not sure.

without getting too far out in the weeds explaining a unitized seal, a conventional lip type seal is installed in the hub and the seal lip rides on and rotates on the seal surface of the load housing. a unitized seal comes assembled with two separate unconnected parts, it is installed in the hub the same as a conventional seal, the inner diameter is a tight fit on the load housing and does not rotate with the hub, the seal surface and rotation is internal in the seal. if the seal is installed with the proper tools and the bearings set to the proper end play a leak usually caused by damage to the hub or the contact surface on the load housing. hope this helps

Kidoo wrote:

crasster wrote:
I'm curious how much oil it is leaking? A gush, small puddle, or just a couple of drops? It can matter when diagnosing over text. :)

At first, it was making a small puddle when I stopped, maybe one inch by two inch. Now, it seen to have slowed down to a line then it stop. I did had oil it and tilted the axle on both side and drove around.

I don't quite understand what you mean by tilting the axle and having oil at each end. Are you sure you are not over filling the diff. with oil? It is full when it runs out the plug on the side where you fill it.

Another cause for wheel seals can be overheating brakes, I don't know if that applies or not. Clogged vent tube as well.
Like said above it may be a problem with the hub if it is the same one that keeps failing.

Kidoo,
This is not all that complicated. You don't say what chassis you have. I'm not all that familiar with Monaco and or, any chassis's they may use, if they're not Freightliner. I replaced my left rear hub seal about 4 years ago or so and it's been fine ever since. Not bragging, not at all. Just saying that it's a simple job and, if yours continues to leak or, at least starts leaking after a repair, obviously something's got an issue.

The seal, normally is installed in the rear of the hub. And, it seals on the axle housing, not the axle itself. I'm not sure what 11178adm was talking about in terms of a "Unitized" seal. And, also not sure what he meant by the statement that it (the seal) "does not rotate". If it's like mine, it HAS TO ROTATE, based on the fact that it's installed in the rear of the hub, and the hub rotates.

Now, I'm presuming that yours is like mine. If it's different, as in a total different design, then all bets are off. But it you take a look at the pics below, you'll see what I'm talking about. In the pics, you'll see the main hub, bearings, removed (bent seal) hub retaining nuts and locking/clocking retaining spacer. The hub it sitting on my table, with the wheel studs facing down. What you see as a silver tooth ring on the back side of that hub is the ABS rotator ring. The seal, fits and is installed, just inside the hub, just inside that ABS ring.

The rear or, inside bearing is installed, then the seal is pressed into position. It's that simple. But, if you're having the trouble with sealing you are, There's some checks that may be in order.
1. Pre-check the seal to axle housing surface with the new seal. Make sure it's a semi-tight fit.

2. Make sure there is no deep grooves from the older seals that were in place before. Even though seals are made of soft material like rubber, neoprene, viton and other substances, it's amazing that sometimes, they will wear in a groove on the housing that they ride on, causing a potential loose fit which can cause a leaking situation.
3. Make sure the seal fits snugly in the hubs housing.
4. The seal, again if it's similar to mine, needs to be installed with great care. That is, it must be installed either with a specific seal installation tool or, at least if the tool is home made, it must be in contact with the entire circumference of the seal-back, as the seal is being either driven in or, pressed in.

If a seal of that size is "hammered" in, in a rotational method, that is if it's pounded in a little at a time, as you pound around the entire seal-back, it's highly possible to warp and or distort that OUTER sealing surface of the seal, the part that seals against the hub, not the rubber side that seals against the axle housing. If it gets warped or distorted, it's possible that, that's where your leak is emanating from.

I have the pictures you see below. But, I do not have a picture of the exact surface your seal rides on, the axle housing itself, in Photobucket, where I store on line photos. Again, if this situation is not like yours, then all this is worthless to you. Good luck.
Scott

crasster wrote:
I'm curious how much oil it is leaking? A gush, small puddle, or just a couple of drops? It can matter when diagnosing over text. :)

At first, it was making a small puddle when I stopped, maybe one inch by two inch. Now, it seen to have slowed down to a line then it stop. I did had oil it and tilted the axle on both side and drove around.

11178adm wrote:
most wheel seals used now are unitized seals, as the seal does not rotate on the axle load housing the sealing is internal inside the seal. make sure that the surface that the area that the seal seats to on the load housing does not have any nicks or gouges in it also check the surface where the seal is installed in the hub. I would check the fit of the seal to the load housing before installing it in the hub it should be a tight fit as that part of the seal does not rotate on the load housing. also check for wear where the bearings ride on the load housing. also were the bearings replaced during the first seal replacement? are they the correct bearings? check the fit of the bearings on the load housing before installing in the hub, they should be a slide fit with no up and down movement.
a very remote possibility if the original seal was a non unitizes seal there should have been a wear sleeve pressed on the load housing, it needs to be removed for a unitized seal

The bearings where not replaced and I do not know if there was a wear sleeve. The first seals where Scotseal 34384, SKF, they both leaked. The second type of seal installed on one side was a National Federal Mogul 370047A, they also put some sealant on the outside. I read somewhere that some seals do not ride on shaft of hub, the ride on themself.

I added about 3/4 gallons in it now, I tilted the axle on both side to make sure I have oil at the end. It does not seem to leak as bad now, it is colder, don't know if it has anything to do with it, no more puddle on the ground when I stop. I used 75/140 as I drive north and south.

I'm curious how much oil it is leaking? A gush, small puddle, or just a couple of drops? It can matter when diagnosing over text. :)

most wheel seals used now are unitized seals, as the seal does not rotate on the axle load housing the sealing is internal inside the seal. make sure that the surface that the area that the seal seats to on the load housing does not have any nicks or gouges in it also check the surface where the seal is installed in the hub. I would check the fit of the seal to the load housing before installing it in the hub it should be a tight fit as that part of the seal does not rotate on the load housing. also check for wear where the bearings ride on the load housing. also were the bearings replaced during the first seal replacement? are they the correct bearings? check the fit of the bearings on the load housing before installing in the hub, they should be a slide fit with no up and down movement.
a very remote possibility if the original seal was a non unitizes seal there should have been a wear sleeve pressed on the load housing, it needs to be removed for a unitized seal