M35A3 Front Axle Leak

[Navo]

I’m about to lose it.... Before I do, I will explain the issue. I bought the truck about 2 months ago. I’m happy as can be, it’s a great truck.

So one day I noticed the passenger side was slinging grease oil mixture. After reading I see that I need to get in there and replace the seals.

OK, So I break down the front passenger hub etc. I replaced the inner and outer seals. While I was in there I noticed the wheel cylinder was leaking and a brake shoe was cracked. So I replace and fix all of those items. Reassemble everything and think to myself. I'll go ahead and do the driver’s side as well.
The driver side was not leaking and didn’t have any know issues. I get busy on that side and discover that also the wheel cylinder is also leaking. So I replace it etc. No other issues on this side. Put it all back together and mount the wheels.

I go ahead and drive it and no problems! Next morning I see oil running down both inner tires. I thought to myself this was residual from when I bleed the brakes. I go ahead and clean it etc. I was gone half the day and when I returned I see it was still dripping. Again, I’m thinking residual....

3 days later.... I think I have another problem. I went under to look at it more closely. The 4 bolts that attach to the spindle housing. The ones on the very bottom that are aligning the king pins. When I tighten them I see gear oil come from behind the boot...On the driver’s side it the same....

WHAT THE ****!!

Any suggestions? Please!

 

[steve6x6x6]

On the front there is no outter seal and what is a spindle housing? I can help but not sure about your parts list. The 4 bolts top and bottom would be the steering kunckle. Did you pull the spindle off to look inside?

 

[Navo]

Hey Steve,

Thanks for trying to help me! I have replaced the the Front Axle Shaft Oil Seal and the the Axle shaft retainer. along with a new boot. I did this on both sides. I also replaced the inner O ring and the Outter O ring.

This is where Im seeing the oil.

 

[G-Force]

Check your axle vent

 

[Navo]

Also cleaned during repairs. And still clear now. You can litteraly clean it and wait 15mins and see a bead of oil.

 

[G-Force]

Did you pull the front axle, u-joint shaft and change the inner seal. Did you install the inner seal with the lip facing inward??? Was the axleshaft suface where the seal rides in good condition???

 

[steve6x6x6]

What is the milage on the truck? Is it gear oil for sure? You can leak gear oil in the boot area even with a new seal, i have seen many trucks with wore out spindle bushings allow the axle shaft to fall down and leak.

 

[Navo]

Did you pull the front axle? Yes

U-joint shaft and change the inner seal? Yes

Did you install the inner seal with the lip facing inward???
Front Axle Shaft Oil Seal For M35 Series, 7521789 / 8738032

If you look at that picture, the side that is on the table is facing the pumpkin.

Was the axleshaft suface where the seal rides in good condition??? Yes

 

[Navo]

What is the milage on the truck? 5,700

Is it gear oil for sure? Yes 90% sure

You can leak gear oil in the boot area even with a new seal, i have seen many trucks with wore out spindle bushings allow the axle shaft to fall down and leak. - Is there any signs that would point to this?

 

[Dukeman]

Did you use RTV or similar sealant around the outside of the seal and the retainer when you reinstalled? Sometimes gear oil will find its way past the seal around its edges, same with the retainer. That is something I have read, not experienced. I just did the same thing on the 5 ton. Put sealant around the seal when it was set in to the retainer. Kept the vehicle jacked up on one side for a couple hours to keep the gear oil to the opposite side and let the sealant set up. I hope that's not the problem, but you are definitely getting gear oil leakage and there are only a couple places that can come from.

 

[Navo]

Did you use RTV or similar sealant around the outside of the seal and the retainer when you reinstalled? Sometimes gear oil will find its way past the seal around its edges, same with the retainer. That is something I have read, not experienced. I just did the same thing on the 5 ton. Put sealant around the seal when it was set in to the retainer. Kept the vehicle jacked up on one side for a couple hours to keep the gear oil to the opposite side and let the sealant set up. I hope that's not the problem, but you are definitely getting gear oil leakage and there are only a couple places that can come from.

You have GOT to be kidding me....I did not use RTV or Silicone..... The seal is installed correctly right? (As I described in my previous post)

 

[gringeltaube]

1) OK, for the seal's orientation.
2) Yes, for using RTV sealant where the retainer is seated. (From factory it comes with some kind of shellack compound, there.)
3) Also YES, for putting some RTV between knuckle/ lower sleeve/ cover plate and also around threads of the 4 bolts (which go all the way through, into the knuckle housing!) - if you want it to stay dry.

FWIW, I have had exactly the same leak spots - both sides! - on a truck that had the front axle completely rebuilt... then parked and not used for months!
Wiped clean but still kept slowly leaking, so obviously it was NOT differential oil!
Result:... it's called oil bleeding, in this case out of relatively full-packed knuckles, with a light type, mineral grease...!
(The problem got fixed, as described in 3))

G.

 

[Navo]

1) OK, for the seal's orientation.
2) Yes, for using RTV sealant where the retainer is seated. (From factory it comes with some kind of shellack compound, there.)
3) Also YES, for putting some RTV between knuckle/ lower sleeve/ cover plate and also around threads of the 4 bolts (which go all the way through, into the knuckle housing!) - if you want it to stay dry.

FWIW, I have had exactly the same leak spots - both sides! - on a truck that had the front axle completely rebuilt... then parked and not used for months!
Wiped clean but still kept slowly leaking, so obviously it was NOT differential oil!
Result:... it's called oil bleeding, in this case out of relatively full-packed knuckles, with a light type, mineral grease...!
(The problem got fixed, as described in 3))

G.

As you stated the seal did come from the factory with the coating on it. I didnt even think of adding the RTV...

Whats weird is when I remove one or two of the bolts no oil comes out. Its like this on both sides. The bolt threads seem to have oil residue on them. On one side it seems to be gear oil and grease. I know its mixed with grease because the color is red (the color of the grease) . I have repeataly sprayed and cleaned the area and bolts with Brake Cleaner with no success.

When I tighen the bolts back you can actually see the oil begining to seep...

I just placed another order with Erik for the oil seals and retainers. If Im going to add RTV to the seal I dont want to take the chance of damaging them when I remove them.

*Sigh*

 

[phil2968]

1)
Wiped clean but still kept slowly leaking, so obviously it was NOT differential oil!
Result:... it's called oil bleeding, in this case out of relatively full-packed knuckles, with a light type, mineral grease...!
(The problem got fixed, as described in 3))

G.

.......I know its mixed with grease because the color is red (the color of the grease) . I have repeataly sprayed and cleaned the area and bolts with Brake Cleaner with no success.

*Sigh*

You said it, the oil is red, the color of the grease. This is because that is where the oil is coming from. You don't have and oil leak from the axle housing. Seal the bolts with RTV and let it be. Some greases weep or bleed more than others. I see it all the time at work with bearing buddies. I pull the cap and there is a lot of red oil under it. I hate to see you do all that work for naught.
Just food for thought, http://www.engineersedge.com/lubrication/bleeding_migration_syneresis_grease.htm

 

[Navo]

You said it, the oil is red, the color of the grease. This is because that is where the oil is coming from. You don't have and oil leak from the axle housing. Seal the bolts with RTV and let it be. Some greases weep or bleed more than others. I see it all the time at work with bearing buddies. I pull the cap and there is a lot of red oil under it. I hate to see you do all that work for naught.
Just food for thought, Bleeding, Migration, Syneresis of Grease - Engineers Edge

On the drivers side there is both gear oil and the red grease oil. on two seperate places. On the passenger side, when I tighten those 4 bolts, fresh gear oil (not red) is leaking behind the boot on the bottom.

So this is my plan, Im gonna break both sides down and replace the oil seal with a new one that will have RTV on it. Also going to RTV the 4 bolts and the plates at the bottom.

 

[Navo]

*****UPDATE*****

I broke the passenger side down again.... and what did I find????? Nothing.

Apparently I was right, when we bled the brakes we didnt have silcone around the opening for the brake line. So some brake fluid, and brake clean went down in the hole and made its way to the bottom...

There was zero sign of the gear oil bypassing the seal. So we cleaned it all up and driained the remaining brake fluid and brake cleaner mixture from behind the boot and made sure all was dry and put it all back together.

I siliconed the two plates on the bottom and used teflon tape on the 4 bolts on the bottm.

SO! Im happy about the results, and I know its dry. I should be able to wake up tomorrow and see dryness.

I know the driver side was put together the same way, so Im gonna wait and let it naturally drain instead of breaking it all down. I might at least add the silicone and teflon tape to the two plates and 4 bolts at the bottom like was suggested and done to the passenger side.

Anyway, hopefully all is well, and that headace is over.

Thanks for your help guys!!!

 

[gringeltaube]

As you stated the seal did come from the factory with the coating on it. I didnt even think of adding the RTV...

Not exactly...! I did say (seal)retainer, not the seal.

Good that the seal you got was coated...; but even so you could still have oil seeping in between the retainer and axle tube, if it wasn't installed with some kind of sealant.

I know, you later found its dry there... still, something to keep in mind next time you or someone else is "in there".




Hope you wake up - "dry"....!



G.

 

[phil2968]

So you put no grease in the knuckle? I thought you replaced the grease. I would like to see how no grease works out in the long run for the u-joint in these axles. I have a friend with these axles under a Chevy. No grease in his either. I know the grease was required for the old style joint.
I thought the boots and the grease kept the water out from the backside of the stub axle and into the hub and wheel bearings.

 

[gringeltaube]

... very true, the last sentence!
Being full with grease also helps to keep the axle shaft thrust washers and bushing inside the spindle, lubricated.

G.

 

[Navo]

Maybe I missed typed. I deffiently added grease! I packed the knuckle and the housing.