Need Some Help with Rear Axle Seal "blow out"

[Commander5993]

Hey everyone, working on my 1986 M1008. I just finished putting in a new fuel tank, sending unit, instrument panel flexiable circuit board, and other to finally get my fuel gauge working, as I had in another thread which I will be updating maybe later tonight.
In any case, when I was under the truck working on the tank, I used the rear tire to push my creeper around. Next thing I knew i had what looked like grease on my hand, so got to looking and saw a little bit of fluid leaking around rear drivers drum.

So I finished up with the fuel system yesterday and got it done early in the day. So I figured I'd go ahead and find out what was leaking on the drivers rear wheel. I pulled the tire, like to never beat it loose from the hub... didn't look that bad rusted or anything when I did get it off. Anyway, I found what appeared to be gear oil and dirt mixed making a grease like substance. So I knew it wasn't brake fluid and figuired it must be the axle seal leaking. Thought about just putting the tire back on and ordering an axle seal and differental cover seal as I saw it was damp around the bottom edge. But later decided to go ahead and pull the axle and drum... I'm glad I did... not what I was expecting. What a mess. Would have never known it was this bad from what little oil was on the backside of the hub.








Like I said, quite the mess. With that said, I've done a few brake shoe and drum jobs, but its been a while. And I haven't worked on any setup quite like the CUCV drum and axle. When I first took the drum off, several peices fell out the bottom which I beleive to be part of the emergency brake, as well as its cable just hanging out toward the bottom of the hub. Also at least one spring is off or broken. Hard to tell exactly until I get everything cleaned up.








Next I started checking out the seal inside the drum and moved the bearings. I don't know if these bearings are supposed to be pressed in? But looking down at the drum like shown above, I can move both inner and outter bearings "up and down". They don't seem to have much slack side to side, which is where I would expect worn bearings would have. I can only assume it is normal to be able to moved them vertically though, as I do understand how they ride on the spindle shaft? on the hub.

I looked at where the bearings ride, cleaned it off some and although it looks like some wear spots on the shaft. I couldn't actually feel any inperfections. Except at the far back "wall", felt like some grooves there. Shown in the two photos below with the last having a red arrow.







So thats where I stopped yesterday. After putting the money in the fuel system, I really didn't want to spend any more $ on the truck right now. But this obviously can't wait, and I want to do it right and have it all fixed and not be redoing a job again.

First I need to get it all dissassembled and clean the entire hub and drum... probably will use at least 5 cans of brake clean for that I did take a paper towel and just clean off a section on the inside of the drum, and didn't feel any grooves or anything. But will have to clean the rest. The shoes have plenty "shoe" left on them, but I'm replacing them all anyway after being soaked in oil. I'm also going to replace the wheel cylinder, spring kit, seals (obviously), and might as well go ahead and replace the bearings too. I'm not sure if there is anything else I should replace or consider, so any input would be appreciated.


I started looking through the TM's last night trying to figure out the correct parts... Can never figure out which manual will have what I'm looking for, so have to look through them all.



Going by the part numbers in the TM's, I've tried to cross them over using Rock Auto part # search. I'm not sure if I'm looking at the best replacment parts, or even the correct one's to be sure. From what I have read, when looking up parts by make/model instead of putting in the actual year we should look at what is listed for a 1984 K30 with the 6.2 disel. Due to this being a military truck and they didn't change parts for multiple years. I have tried this also, and usually come up with more part options than just by crossing the part #. I know some of the options will not match, but some of them do. Just different brands or etc that show being available that don't come up using just the part #.

In any case, here is what I have so far crossing the part # from the TM's using Rock Auto:



Wheel Hub Retainer/Lock Ring
TM 341511 - DORMAN 615141

Outter Wheel Bearing:
TM LM104949 - TIMKEN LM104949
* Race:
TM LM104911 - TIMKEN LM104911

Inner Wheel Bearing:
TM 387AS - TIMKEN 387AS
*Race:
TM 382A - TIMKEN 382A

Wheel/Axle Seal:
TM 469694 - TIMKEN 2081
**(I don't know what part # I crossed this from, but I also had a TIMKEN 8835S seal in the cart. I know I crossed this from another number out of the TM's last night, but now I can't seem to find it)

Wheel Cylinder:
TM 18004890 - RAYBESTOS WC37048


These below I looked up by Make/Model:

I don't know if bonded or rivited shoes are better?
**I am pretty sure the drums are 13 x 3.5"

Shoes:
ENTRIC 11104520 (bonded)
RAYBESTOS 452PG (rivited)
would rather have AC Delco, but they are twice the price.

Drum Hardware/Spring Kit (these kits does both wheels right?)
ACDELCO 18K561


Differental Cover Gasket for 10-1/2 IN Ring Gear, w/ 14 Bolt Holes:
MAHLE P28128 (paper)
DANA RD51995 (reusable "mechanically and chemically bonder woven steel")


I can't find a part # for the front Diff Cover (as I'm going to replace that one too when I change fluid), some threads on here said just use RTV.

To change the fluid in both front and rear differentals, looking at the FAQ's I think I'll need 5 quarts (10 pints) of 80w-90 gear oil?


Ok... sorry for such a long post. But does anyone else know of what else I might need?? Any opinions on any of this??
As I said, I've changed brake shoes before... I don't like them... and I've also never worked on this heavy of an axle before.
So Any input would be Greatly Apprciated

~Thanks All

 

[porkysplace]

Use TM 9-2320-289-34P for a parts diagram Page 274.
Also check for a plugged axle vent

https://www.steelsoldiers.com/upload/CUCV/tm9-2320-289-34p.pdf

 

[Commander5993]

Use TM 9-2320-289-34P for a parts diagram Page 274.
Also check for a plugged axle vent

https://www.steelsoldiers.com/upload/CUCV/tm9-2320-289-34p.pdf

View attachment 890154

View attachment 890151

Yeah, I finally found that diagram. Thats where I got some of the part numbers from. Got some of the other part numbers from that same TM on page 297.

I'll have to check the vent you mentioned

I think the one peice that is laying on the floor in the 4th photo I posted, the part that is "bent" is supposed to be straight. It looks like part 21 in the diagram you posted here. I don't see any other part that it could be, as none are made the way it is currently shaped. I wasn't able to start cleaning it up today, will try to get that done tomorrow so I can see everything and know for sure.

 

[porkysplace]

Yeah, I finally found that diagram. Thats where I got some of the part numbers from. Got some of the other part numbers from that same TM on page 297.

I'll have to check the vent you mentioned

I think the one piece that is laying on the floor in the 4th photo I posted, the part that is "bent" is supposed to be straight. It looks like part 21 in the diagram you posted here. I don't see any other part that it could be, as none are made the way it is currently shaped. I wasn't able to start cleaning it up today, will try to get that done tomorrow so I can see everything and know for sure.

What might be the way to go is pull the drum off the other side (probably should do both seals anyway ) and use that side for a guide . Only do one side at a time .
Edit: part #21 is part of the self adjuster assembly one end should be wider than the other end, that end goes over the shoe and self adjuster arm

 

[WWRD99]

Yeah, I finally found that diagram. Thats where I got some of the part numbers from. Got some of the other part numbers from that same TM on page 297.

I'll have to check the vent you mentioned

I think the one peice that is laying on the floor in the 4th photo I posted, the part that is "bent" is supposed to be straight. It looks like part 21 in the diagram you posted here. I don't see any other part that it could be, as none are made the way it is currently shaped. I wasn't able to start cleaning it up today, will try to get that done tomorrow so I can see everything and know for sure.

You got a live one there!!! The bar that is bent on the floor goes under the wheel cylinder in the notches on each shoe. You are missing spring 22 that goes on the one end of that bar. The parking brake bracket that's laying next to the bent bar goes through the self adjuster part 16 if you follow the pic 115 left the part on the floor is dead center of the pic but no diagram number. I bet if you look at the pic 115 you'll see how that works. The other spring you're missing is spring 24 and I'd bet when that failed that's when everything fell apart. On my eye the shoes look pretty thin especially if they are riveted. You measure them on the top of the rivet head see how much shoe is left. I am not sure if I'd try to clean that drum but take it to a machine shop and get them to cook it to get that oil out. 10 cans of brake clean will easily out price a cook at the shop!! Plus they can remove and install the new races, which can be a pain since they are huge!! You can take the bearings out and see what's in there and cross those. I do recommend Timkin bearings. Being a gm 14 it shouldn't be tough to find parts for it. Definitely check the breather!! Good luck and keep posting if you need help!

 

[WWRD99]

Yeah, I finally found that diagram. Thats where I got some of the part numbers from. Got some of the other part numbers from that same TM on page 297.

I'll have to check the vent you mentioned

I think the one peice that is laying on the floor in the 4th photo I posted, the part that is "bent" is supposed to be straight. It looks like part 21 in the diagram you posted here. I don't see any other part that it could be, as none are made the way it is currently shaped. I wasn't able to start cleaning it up today, will try to get that done tomorrow so I can see everything and know for sure.

Ok so I looked at the pics you posted of the spindle and the red arrow....That looks like the bearing spun on the hub. Outward from the red line the shiny metal gets dark like not machined...right at that point it looks like there's a lip there as well which there shouldn't be one. What happens when the bearing spins on it's inner race it eats the spindle and can let the drum rock and then leak oil. You will have to measure that bearing area on the hub to see if it is worn beyond spec. The bearing should slide on the hub easily and the inner race should not wobble on the hub.

 

[87cr250r]

You'll want to replace your wheel cylinder. The axle oil will damage the rubber components on the wheel cylinder. It's also possible the wheel cylinder was the source of the oil. Remember, these trucks use a silicone oil for the brakes instead of traditional brake fluid.

 

[porkysplace]

You'll want to replace your wheel cylinder. The axle oil will damage the rubber components on the wheel cylinder. It's also possible the wheel cylinder was the source of the oil. Remember, these trucks use a silicone oil for the brakes instead of traditional brake fluid.

The smell of it should tell you if it's gear oil or brake fluid .

 

[Commander5993]

What might be the way to go is pull the drum off the other side (probably should do both seals anyway ) and use that side for a guide . Only do one side at a time .
Edit: part #21 is part of the self adjuster assembly one end should be wider than the other end, that end goes over the shoe and self adjuster arm

Yeah using the other side to 'copy' would be ideal... but I actually do not have enough room in the shop to remove the other side as it is right up against a huge shelf unit. I barely was able to sqeeze the truck in there, and make room to work on fuel tank, and as such could get to the drivers side hub. Even if I turn the truck around and pull in, I don't know if I can get to the passengers side hub, as it will be near the garage door where another big 10ft tall metal shelf unit is. I may have to wait for warm weather and do the passengers hub outside. Its been really cold and got a inch of sleet and freezing rain a couple days ago. Got about 10 inches of snow before that. And thats a lot of deep south missouri.

 

[Commander5993]

You got a live one there!!! The bar that is bent on the floor goes under the wheel cylinder in the notches on each shoe. You are missing spring 22 that goes on the one end of that bar. The parking brake bracket that's laying next to the bent bar goes through the self adjuster part 16 if you follow the pic 115 left the part on the floor is dead center of the pic but no diagram number. I bet if you look at the pic 115 you'll see how that works. The other spring you're missing is spring 24 and I'd bet when that failed that's when everything fell apart. On my eye the shoes look pretty thin especially if they are riveted. You measure them on the top of the rivet head see how much shoe is left. I am not sure if I'd try to clean that drum but take it to a machine shop and get them to cook it to get that oil out. 10 cans of brake clean will easily out price a cook at the shop!! Plus they can remove and install the new races, which can be a pain since they are huge!! You can take the bearings out and see what's in there and cross those. I do recommend Timkin bearings. Being a gm 14 it shouldn't be tough to find parts for it. Definitely check the breather!! Good luck and keep posting if you need help!

I think it was on life support lol
I see the part you are refering to. I did clean up most of it today, and found that spring you are refering to. As well as several other parts and springs. I'll post about that in a bit in an update.
I wish there was a machine shop around here, I could have used one many time in past years. But closest one is probably about 70 miles away. We are out in rural cattle country here. I actually didn't know there was any other way to clean a drum except by solvents. I did end up using 3 cans of engine degreaser and proabaly 8 cans of brake clean today. And I still could use a couple more to finish cleaning up the back plate.

Probabaly not the best way... but I was able to remove the races and bearings, a press would have made it a lot easier though. I found a guy on youtube that showed how he did these without a press. Now I just got to know how to put the new one's back in

**Video for future reference to anyone who might need it:

And Yes, I also like Timkin bearnings. Used to sell them when I worked for an autopart supplier some years ago.

Found the breather today, and I'm sure its clogged too. Have to clean it still.

 

[Commander5993]

Ok so I looked at the pics you posted of the spindle and the red arrow....That looks like the bearing spun on the hub. Outward from the red line the shiny metal gets dark like not machined...right at that point it looks like there's a lip there as well which there shouldn't be one. What happens when the bearing spins on it's inner race it eats the spindle and can let the drum rock and then leak oil. You will have to measure that bearing area on the hub to see if it is worn beyond spec. The bearing should slide on the hub easily and the inner race should not wobble on the hub.

Ok.... I've heard of spun bearings, but never ran into the problem before. I couldn't feel anything on the spindle except where I have the red arrow pointing at the "wall" where it bumps up to the larger diameter part of the spindle. On the flat part of the shaft, even though there was some places where it looked scuffed or something I couldn't feel any imperfections. The races also looked good too, although they will be harder rockwell than the spindle of course.

I will look up the hub specs and measure it. Since I have the bearings pulled, I'll also slide them up on the hub and just see what I can tell from that too. I sure hope I don't have to replace the hub...

 

[Commander5993]

You'll want to replace your wheel cylinder. The axle oil will damage the rubber components on the wheel cylinder. It's also possible the wheel cylinder was the source of the oil. Remember, these trucks use a silicone oil for the brakes instead of traditional brake fluid.

Yep, I'm replacing basically all of it for both sides. Do it once, cry once, and hopefully won't ever have to take all of this apart again.
And yes, I have a gallon of DOT 5 Silicone brake fluid. I'll probably go ahead and flush the system when i get this done. But I'm going to check out the front calipers, rotors, and pads too. Now that I think of it, I may need some more fluid to flush the whole system, not sure how much it holds plus bleeding out of the air etc.

 

[Commander5993]

The smell of it should tell you if it's gear oil or brake fluid .

it is oil, no doubt. And it was baked on too... literally scraping it off. I'm sure the brake dust that was previously in there, plus plenty of dirt made it like thick tar.

 

[87cr250r]

Timken doesn't sell their own bearings. This applies for all aftermarket suppliers. What was good yesterday may be different today. Always keep this in mind.

 

[87cr250r]

The DOT 5 thing is funny. There is zero difference between DOT 3 components and DOT5. But, if you mix the fluids it will ruin the components. When I bought my truck there was DOT 3 in the brake system and it caused the diaphragm on the master to swell in that chamber. The rear wheel cylinders failed eventually later.

 

[Commander5993]

Ok all, caught up on the replies. Sorry I hadn't replied sooner, been having a lot of problems with my starlink internet. Then my desktop computer went down and won't even boot. AND my laptop got some malware that copied itself into my google chrome sync, so even when I gave up and wiped the hard drive and reinstalled windows, when I would re-sync my chrome info the malware would copy itself right back onto the computer. Spent hours last night just trying to get a virus remover to work, then trying to get rid of it manually out of my chrome sync info. Ended up having to erase most of my sync info, at least got to keep my saved favorites/bookmarks which are a collection made up from the last 20 years...

ANYWAY, I spent all day today trying to get this hub and drum cleaned up. This stuff was literally like Tar. I used 3 cans of engine degreeser and about 8 cans of brake clean, scraping it with a screw driver and other various utensils. Still need a couple more cans of brake clean to finish cleaning the hub, as I have not removed the wheel cylinder yet, as I don't want it dripping brake fluid for a week while I wait on parts.


As I mentioned in one of my replies above, I did get the bearings and races out of the drum.... or the hub part of the drum. I didn't take the drum apart, as I didn't want to remove the lug bolts. But man that thing is heavy...

Anyway, after getting the drum cleaned up the pad surface is smooth. Didn't see or feel any grooves or etc.




But... what I did run into was metal flakes. As I was cleaning I started seeing them on my gloves, then on the paper towel. Then found more inside the hub, which at the time I figured they had come through by the axle shaft and got past the seal.



When I first saw the shavings, I thought it could have been from the oil getting to low and the differential beginning to eat itself. So I stopped cleaning, and pulled the diff cover. There was more fluid still in there than I expected, given how much was inside the drum. And I didn't see any "magic sparkles" in the oil, or in the bottom of the differential case. It was clean.



So I thought it could have been from one of the wheel bearings and "all was good" because i was replacing them anyway.

....but now that I think of it WWRD99, a spun bearing could indeed be what the shavings are from. So I may have to replace the spindle/hub shaft I hate to even look up to see what they may cost.
EDIT: Actually, can you even just replace the shaft that the bearings ride on? Or it is all "one part" of the entire axle/differential???

Anway, after that I went back to cleaning. Pulled all the shoes, springs, and etc. But I left the wheel cylinder for now until I get the new one, which I haven't even ordered yet as I was hoping to get it everything on one parts order. Which is why I wanted to get this all cleaned up today so I would know if there was anything else that I needed.... which I was only expecting a small odd and end item though...

After spending all day and well into tonight, a trash can full of:
empty solvent cans, soft steel brush, many pairs of gloves, roll and half of blue towels, card board, plastic bags, half a bag of oil dry, and what was left of my patience...

I can at least see bare metal on most of the back plate. Still needs some more cleaning, but its almost there.

 

[Commander5993]

The DOT 5 thing is funny. There is zero difference between DOT 3 components and DOT5. But, if you mix the fluids it will ruin the components. When I bought my truck there was DOT 3 in the brake system and it caused the diaphragm on the master to swell in that chamber. The rear wheel cylinders failed eventually later.

well thats just great... I knew this... but ever since my TBI my focus/memory has been shot (which is also why I also take so many photos when I'm working on something) And I think I may have topped off the master once with DOT 3, but I'm not sure. Which is one of the reasons I was going to flush the entire system now. I thought DOT 3 & 5 just didnt "get along" rather than damaging components. As you said, all the components, seals, etc are the same.

Certainly isn't the first time that my memory has cost me...

 

[nyoffroad]

Well, I guess now that your done cleaning it's a piss poor time to chime in, buttt. A plastic tote and a couple of gallons of kerosene and a parts brush would've cleaned that right up. Don't worry you can thank me later
Those metal flakes you mentioned, they may be from the spring and other break parts that bounced around inside the drum for who knows how long. I doubt the bearing spun as the only reason that would happen is a lack of lube and even then the bearing would be locked or partially locked up to spin on the hub. I think your gonna be fine, remember a loose bearing is better than a tight bearing! (Not saying leave it loose)

 

[87cr250r]

The bearings are clearance fit on the spindle and can and will spin which wears down the spindle. My truck has worn spindles.

 

[Commander5993]

Well, I guess now that your done cleaning it's a piss poor time to chime in, buttt. A plastic tote and a couple of gallons of kerosene and a parts brush would've cleaned that right up. Don't worry you can thank me later
Those metal flakes you mentioned, they may be from the spring and other break parts that bounced around inside the drum for who knows how long. I doubt the bearing spun as the only reason that would happen is a lack of lube and even then the bearing would be locked or partially locked up to spin on the hub. I think your gonna be fine, remember a loose bearing is better than a tight bearing! (Not saying leave it loose)

i don't know why I didn't think to take a gas can get some kerosene. I think there is one gas station in town that does have it.
Who ever reads this post later that needs help can thank you

and yeah, it could be from the other parts. with everything covered in a think layer of gunk, it was hard to tell. I did clean up the hub to a degree while everything was still in tact. Just so I could take some photos for later reference, even though some of the parts were missing.