Rear axle seal leak

[kenn]

When I bought this deuce there was a very small leak around the inside of the tire. I thought it might be a wheel cylinder but the smell was a dead giveaway that it was gear oil. The last couple of times I took it for a short drive, it went from a small leak to leaving a puddle under the tire. I already have the parts from big mikes so I've decided this is next on the maintenance agenda. On disassembly everything outside and inside are coated with gear oil so I'm sure that brake wasn't doing much, lol. That might explain why the temp was so low compared to the others -- no friction! Also the little cork stopper was squished flat. There was so much oil in there that most of the grease was washed out but the bearings still look pristine given they were in a gear oil bath. Also the inner hub nut was essentially hand tight. I just took in off with my fingers -- no torque needed.

I have the inner hub seals as part of the kit I got. Should I go ahead and replace them or leave them be? I know they are essentially there to keep grease in and dirt out. If they aren't visibly damaged it just seems like removing them and putting new ones in introduces additional possibility of error and of course introduces chinese parts. I'm going to use the gray RTV or possibly "The Right Stuff" that I've seen posted elsewhere in the keyway instead of cork. I'll post up when I'm done and the results.

I also had one wheel lug nut bite so hard on the inner lug that it backed out the inner lug before coming off. To separate them, I soaked with PB blaster and held the lug nut with a large crescent and used a 12 point 15/16 socket over the square-tipped stud to work it in/out until enough lube was on the threads to loosen things up and I finally worked them apart. Nothing is ever simple, lol.

And yes, I'll check the wheel cylinder while I'm there.

 

[msgjd]

had one wheel lug nut bite so hard on the inner lug that it backed out the inner lug before coming off

hate it when that happens !!! .. what also can happen is if one pushes in on the impact, sometimes the square hole in the dual-purpose socket engages with the inner stud , the result is the same ... I found out the hard way, more than once the same morning,, until I figured out what was going on The BN Maint Sgt had a good laugh at my expense. Well in my defense, up to that point I had only changed out duals that were open-center daytons and single-fastener budds.. ..
As for your seals, you should check to see if your replacement seals are dual-lip, triple is even better ... For the time involved, I would not install any single-lip seal anywhere in the driveline of a 6x6 anywhere, if I had a choice

 

[kenn]

I'm not sure I understand single-lip vs. dual/triple for the inner axle seal. The seal that is on there now has a single "rubber" flange. The set I purchased looks quite similar. I'm not seeing any 2 or 3-lipped inner axle seals at any of the vendors.

 

[INFChief]

What year & model deuce is this? I don’t remember a rear axle seal but remember inner & outer hub seals. I thought the axle was sealed but the gasket on the axle flange.

 

[msgjd]

I'm not sure I understand single-lip vs. dual/triple for the inner axle seal. The seal that is on there now has a single "rubber" flange. The set I purchased looks quite similar. I'm not seeing any 2 or 3-lipped inner axle seals at any of the vendors.

When we did axle seals on 5-tons up to a decade ago, double-lip seals were available, some even shared the same part number as the singles which is odd. On occasion we were told by suppliers that some triple-lips (flange) had been located at certain warehouses thus we got those too.. I understand you are doing a deuce axle and we have not yet had the need to change any on the deuces since those I have left have always done mostly-stationary tasks.. But the seal purpose is the same. Any additional "flange" on a seal basically supplements the primary flange and we have found them to last longer in keeping gear oil from contaminating bearing grease, or in the case of front axles, from leaking out the boots and other spots. They also give better protection to keep contaminants from getting in .. They also seem to handle possible buildup of internal pressure better, such as a plugged axle vent, supposedly takes more to "blow" them out .. Even if the original seal was a single lip, we shopped around for something better .. We had too many trucks to maintain with limited manpower, some working jobsites daily in dirt, dust, water and mud up to axle deep .. If we had to replace seals once, we didn't want to be doing it again for a very long time.. It is possible suppliers today can no longer obtain the type I am mentioning . They were not easy to find back then, and certainly not "on the shelf" at the downtown NAPA or what have you, but they were out there .. This all boils down to what tasks anyone's trucks are expected to do, what their work or recreational environment is, how often they use their truck, and how often one wants to replace seals

 

[INFChief]

Maybe it’s just the pictures; but, it looks like a couple of wheel lug nut studs are pushed back in. Also, in the one photo it seems as if the gear lube (GL) is dripping out from the hub & not the center bore of the axle housing where the axle slides in.

I simply do not remember 2.5 tons have inner axle seals except on the front.

If you are getting axle oil (GL) in to the brakes then that GL has to leak past the flange seal and wick back up into the hub and then on to the brakes. I suggest you remove the brakes (which you will need to do anyway) and clean everything up real good & look for cracks in the axle housing at the brake hardware backing plate.

I have no idea what the bearings were packed with but if it was grease it might have been a lightweight type. Wheel bearing grease is generally thicker and holds up heat without breaking down so bad.

 

[kenn]

What year & model deuce is this? I don’t remember a rear axle seal but remember inner & outer hub seals. I thought the axle was sealed but the gasket on the axle flange.

Thanks again! I think I mis-stated -- MY BAD! Inner Hub Seal!!! 1970ish M35A2. I'm calling the "inner seal" the one that blocks dust out and keeps grease in and I can't find anything that appears to be double lipped (or triple). On what I'm calling outers, the stock one is the one that appears to have those little lines in the seal and appears to have a double rubber lip. The replacement I got from Mikes does as well. The "inner" seems to have been put on by someone with two left hands and is slightly bent so I'll remove and replace after all.

 

[kenn]

Maybe it’s just the pictures; but, it looks like a couple of wheel lug nut studs are pushed back in. Also, in the one photo it seems as if the gear lube (GL) is dripping out from the hub & not the center bore of the axle housing where the axle slides in.

I simply do not remember 2.5 tons have inner axle seals except on the front.

If you are getting axle oil (GL) in to the brakes then that GL has to leak past the flange seal and wick back up into the hub and then on to the brakes. I suggest you remove the brakes (which you will need to do anyway) and clean everything up real good & look for cracks in the axle housing at the brake hardware backing plate.

I have no idea what the bearings were packed with but if it was grease it might have been a lightweight type. Wheel bearing grease is generally thicker and holds up heat without breaking down so bad.

I am busy pulling the whole thing apart to clean it as it is seriously gunked up. That said, there was GL inside the shaft housing and coating the axle. It has now been sitting jacked up for a couple of days leaning inward, of course, and I did wipe out the tube. The inner nut was really loose and the cork seal mashed so clearly gear oil was easily making it into the hub. There was a lot more at the end of the hub and quite a bit inside but not nearly as much behind the flange seal as you called it. I guess I'll know once I have it completely apart.

 

[M35A2-AZ]

Do not forget to put the cork or RTV in the keyway.

 

[INFChief]

Thanks again! I think I mis-stated -- MY BAD! Inner Hub Seal!!! 1970ish M35A2. I'm calling the "inner seal" the one that blocks dust out and keeps grease in and I can't find anything that appears to be double lipped (or triple). On what I'm calling outers, the stock one is the one that appears to have those little lines in the seal and appears to have a double rubber lip. The replacement I got from Mikes does as well. The "inner" seems to have been put on by someone with two left hands and is slightly bent so I'll remove and replace after all.

IMO, the OEM seals always worked fine. Of course now & then you simply get a bad new seal.

As said below by another member be sure to seal up that keyway. The outer seal is supposed to keep dirt, dust, water, and GL from leaching in. Use a new axle flange gasket too.

With the bearing nuts loose that could be a sign of a sloppy reassembly or possiblythe grease breaking down. I don’t know what the TM says but we would tighten the inner bearing nut until it was TIGHT (bearing crush) then back it off till loose then retighten to good & snug (not too tight). The wheel should spin freely and not bind. Then we would put the special washer in then the outer nut. Some of the washers had tabs that would be bent over a flat spot on the nut to “lock” the nut to prevent it from loosening & turning off. Don’t forget the outer hub seal in this process.

This thread brings back some very old and very cool memories!

 

[kenn]

and... the wheel cylinder is definitely bad. I'm done for the day as it's too hot to continue. I have it all apart and cleaned so next up is to replace the wheel cylinder, re-pack the bearings, and reassemble. More to come.

 

[G744]

Some have hassled me about my method of getting all the oil out of your brake shoes, but soaking them in a pan with gasoline for a day is the first step.

Then put them on some kind of grill and set them on fire. They'll burn for a while, just leave them alone and let them cool. Put them back in.

Works fine, and they get just as hot on the job driving in the mountains.

DG

 

[kenn]

Maybe it’s just the pictures; but, it looks like a couple of wheel lug nut studs are pushed back in.

I hadn't notice that on disassembly but yes, one of the studs doesn't seem to be pressed in all the way. Given these were torqued down very, very tight, I assume there is/was some crud/corrosion in/around the stud hole when it was pressed in. The stud was certainly long enough to have enough to provide plenty of purchase for the lug nut so I'm not sure what to do here. I guess press it out, clean it up, and press it back in?

 

[INFChief]

Some have hassled me about my method of getting all the oil out of your brake shoes, but soaking them in a pan with gasoline for a day is the first step.

Then put them on some kind of grill and set them on fire. They'll burn for a while, just leave them alone and let them cool. Put them back in.

Works fine, and they get just as hot on the job driving in the mountains.

DG

I would not recommend that technique. At worse, I would try to dissolve & ‘blow off’ the grease with a Brake-Kleen type product. But grease or oil seeps in to the brake shoe material pretty deep and there’s no way to get it all out. Separation from swelling or contracting is pretty likely and neither result is good - swelling shoes could heat up the drum to the point of ignition; barring a outright fire, at a minimum it could result in having to replace shoes, drum, seals, bearings, and brake hardware.

Even if I only drive this truck 1 mile per year I would replace the liners or the liner /shoe assembly. Much cheaper than rolling the dice & losing.

 

[bprzyw]

Some have hassled me about my method of getting all the oil out of your brake shoes, but soaking them in a pan with gasoline for a day is the first step.

Then put them on some kind of grill and set them on fire. They'll burn for a while, just leave them alone and let them cool. Put them back in.

Works fine, and they get just as hot on the job driving in the mountains.

DG

Funny you should mention this as my grandfather used to do this very thing.

 

[ToddJK]

Some have hassled me about my method of getting all the oil out of your brake shoes, but soaking them in a pan with gasoline for a day is the first step.

Then put them on some kind of grill and set them on fire. They'll burn for a while, just leave them alone and let them cool. Put them back in.

Works fine, and they get just as hot on the job driving in the mountains.

DG

My uncle who's been a life long mechanic has done similar, but he would use a torch on a low setting and keep the shoes around a certain temperature. I was young and didn't ask the right questions, but I remember something along the lines of "drying them out" lol.

 

[kenn]

I finally got some time this morning to get back after it. I cleaned the brake backing plate and everything else all the way back to and through the hub. I degreased the wheels and tires and pressure washed them clean (off of the truck). I used gear oil RTV to seal the keyway and put a new gasket over the axle cover and buttoned it up.

As I've crawled around under there I can see some gear oil and/or brake fluid in the other three inner wheels so I'm going to just pull them all.

Out of curiosity, I pulled the fill plug for the rear diff and it was about 1 knuckle below spilling out.

I also ordered all new brake lines (5 flexible ones) so I'll be doing that as part of this adventure. I'll also be replacing the axle vent as it looks questionable.

 

[Mullaney]

I finally got some time this morning to get back after it. I cleaned the brake backing plate and everything else all the way back to and through the hub. I degreased the wheels and tires and pressure washed them clean (off of the truck). I used gear oil RTV to seal the keyway and put a new gasket over the axle cover and buttoned it up.

As I've crawled around under there I can see some gear oil and/or brake fluid in the other three inner wheels so I'm going to just pull them all.

Out of curiosity, I pulled the fill plug for the rear diff and it was about 1 knuckle below spilling out.

I also ordered all new brake lines (5 flexible ones) so I'll be doing that as part of this adventure. I'll also be replacing the axle vent as it looks questionable.

.
The "one knuckle" measurement is a good safe fill level for the differentials.
Not too much.
Not too little.
Kinda like the Three Little Bears - Just Right...

 

[kenn]

It appears that just maybe the rear driver and intermediate lugs haven't been removed in a very, very long time. Inner lugs aren't coming out. I don't want to buy a $300 impact as my compressor isn't going to drive it without burning it up. Off to google and a little searching and I found a lug nut torque multipler for under $100 that will produce an insane amount of torque. It is essentially a planetary gear reduction and they come in 58:1, 64:1, and 86:1 for rough torque strength of 4 to about 7 thousand foot pounds. Google search "lug nut torque multiplier wrench" or something similar and you'll find it. I watched a couple of videos on youtube and a guy walked a 1 1 /2" lug off by hand that previously bent his breaker bar (like I've done, lol).

If you have huge nuts that need to be handled, this may be the answer. It's so easy, even your wife can do it. It even goes both ways. Man, these write themselves, lol.

 

[bprzyw]

Yeah!!!! Mine have not been touched since 89.