Knuckle Oil Leak after rebuild? (1 Viewer)

[TheMindofJ]

I just rebuilt the front axles a month ago. While changing my oil I noticed some moisture/oil buildup on the bottom of the knuckle/arms (sorry don’t know what everything is called), however there is no grease leaking onto the knuckle itself. That is an old stain on the knuckle so disregard that. Any ideas?

 

[bhsdriller]

Looks normal to me

 

[jpoole]

The oil in grease tends to separate out over time and is too thin to be held in the knuckles, so runs down like this. You likely see the same thing on your grease guns, that get oily after sitting with grease in them for a while. In my opinion this doesn't indicate any problem and is just how it is.

When internal seals fail you see much more grease and or a gear oil and grease mixture flowing out and getting slung around on the wheel/etc.

 

[Rusty Marlin]

Same as above. You'll know it when there's an axel seal blowout. You won't need to question it, there is ZERO doubt.

 

[BILT4ME]

I just rebuilt the front axles a month ago. While changing my oil I noticed some moisture/oil buildup on the bottom of the knuckle/arms (sorry don’t know what everything is called), however there is no grease leaking onto the knuckle itself. That is an old stain on the knuckle so disregard that. Any ideas?

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I would be more concerned that your balls are as dry as they are.

Is there really grease in there?

Did your rebuilder clean the axle housing vent and hose and fitting when it all got rebuilt? If you recently drove it and got it nice and warm, if it cannot vent, it will tend to push gear oil into the knuckles. Then, as it cools it sucks grease back from the knuckles into the differential. Then you end up with Birf Soup. All because the axle housing vent was not properly serviced or changed to a long hose with a filter up by the booster to prevent water intrusion during a water crossing.

 

[jpoole]

Yeah, there should be a thin, residual grease film on the knuckle balls left behind by the wiper seals when steering turns the wheels. If you look carefully you can often get a sense of how much grease is in the knuckles by finding the top edge of this grease film. You want to see the grease covering most of the knuckle ball, excepting a small amount up high.

If you don't have an obvious grease film then you should add some moly grease via the square headed fill plugs and then re-evaluate. You may end up wanting to add grease a few times until you bring the levels up above mid-level at least. You can probably find an official / recommended fill level (like 3/4 full) on mud somewhere but I personally like to run mine pretty high. The few times I've overfilled a knuckle there was excess grease pushed past the wiper seals on the first few heat cycles and then the film left on the knuckle balls went back to normal.

Along with the vent/hose the elbow on the axle that the vent connects to should also be removed and cleared as it can get blocked as well.

If you are curious if that oil/fluid on the bottom of the knuckle is possible from the diff you can smell it to figure it out. Gear oil has a pretty distinctive smell that your grease should not have.

 

[TheMindofJ]

bilt4me & jpoole thanks for prompt responses… I did the rebuild myself and watched an hour YouTube video about it that did not mention anything about an axle housing vent. Damn I wish I had known that. I haven’t driven this in 3 weeks - could that be a reason the balls look dry?… I packed a lot of grease in there… gonna continue reading and tinkering around

 

[BILT4ME]

bilt4me & jpoole thanks for prompt responses… I did the rebuild myself and watched an hour YouTube video about it that did not mention anything about an axle housing vent. Damn I wish I had known that. I haven’t driven this in 3 weeks - could that be a reason the balls look dry?… I packed a lot of grease in there… gonna continue reading and tinkering around

The easy way is about 5 ft of 1/4" fuel line and a 1/4" fuel filter and a few hose clamps.

The fitting on the axle housing unscrews with a threaded pipe fitting.

 

[Malleus]

I would be more concerned that your balls are as dry as they are.

Is there really grease in there?

Did your rebuilder clean the axle housing vent and hose and fitting when it all got rebuilt? If you recently drove it and got it nice and warm, if it cannot vent, it will tend to push gear oil into the knuckles. Then, as it cools it sucks grease back from the knuckles into the differential. Then you end up with Birf Soup. All because the axle housing vent was not properly serviced or changed to a long hose with a filter up by the booster to prevent water intrusion during a water crossing.

This is becoming an epidemic...

 

[TheMindofJ]

The easy way is about 5 ft of 1/4" fuel line and a 1/4" fuel filter and a few hose clamps.

The fitting on the axle housing unscrews with a threaded pipe fitting.

Is this something I can do without taking the knuckle apart?

 

[jpoole]

He's just saying that you can replace the factory axle vent hose/etc. with fuel line/filter. Personally I'd just clean and continue to use the factory setup unless you have extra lift or are prepping for deep water fording.

The axle breather system is simple to remove/clean/reinstall and you shouldn't need to buy any parts or take any other part of the axle/80 apart to do this work. Grease/oil/grit can build up in the 90 degree elbow that's screwed into the axle housing, in the hose itself or in the vent trap device that the hose connects to (on the non-axle end). Just clean all of those things out and you should not have any axle ventilation issue.

You don't appear to have a clogged vent or blown inner axle seal. You'd see a greenish soup slurry of gear oil and grease slung all over the leaking axle end if the seal had failed, or at least the start of this mess. Cleaning the vent system is easy and a good idea if you haven't done this service work before on your 80, even if yours aren't clogged.

The apparent lack of grease on the knuckle could just be a combination of it being recently serviced/clean and the photo itself. If you know you put grease in there and it's running quietly I wouldn't worry too much. I'd still add grease if you think it's low so that you know you've got plenty in there and I would keep an eye out for the grease film on the knuckle balls which should show up after a few heat cycles and normal driving. Adding moly to the knuckles is a regular service item that you need to be setup to do anyway. I keep a grease gun with moly grease in it specifically for adding to the knuckles periodically. I add 30-40 pumps every 6 months, roughly, and keep an eye on the film level as mentioned above whenever I'm down there.

 

[TheMindofJ]

He's just saying that you can replace the factory axle vent hose/etc. with fuel line/filer. Personally I'd just clean and continue to use the factory setup unless you have extra lift or are prepping for deep water fording.

The axle breather system is simple to remove/clean/reinstall and you shouldn't need to buy any parts or take any other part of the axle/80 apart to do this work. Grease/oil/grit can build up in the 90 degree elbow that's screwed into the axle housing, in the hose itself or in the vent trap device that the hose connects to (on the non-axle end). Just clean all of those things out and you should not have any axle ventilation issue.

You don't appear to have a clogged vent or blown inner axle seal. You'd see a greenish soup slurry of gear oil and grease slung all over the leaking axle end if the seal had failed, or at least the start of this mess. Cleaning the vent system is easy and a good idea if you haven't done this service work before on your 80, even if yours aren't clogged.

The apparent lack of grease on the knuckle could just be a combination of it being recently serviced/clean and the photo itself. If you know you put grease in there and it's running quietly I wouldn't worry too much. I'd still add grease if you think it's low so that you know you've got plenty in there and I would keep an eye out for the grease film on the knuckle balls which should show up after a few heat cycles and normal driving. Adding moly to the knuckles is a regular service item that you need to be setup to do anyway. I keep a grease gun with moly grease in it specifically for adding to the knuckles periodically. I add 30-40 pumps every 6 months, roughly, and keep an eye on the film level as mentioned above whenever I'm down there.

Great thank you. Thanks everybody for helping me cure my dry balls

 

[BILT4ME]

Great thank you. Thanks everybody for helping me cure my dry balls

Always remember:

Lube your shaft
Check your nuts
Keep your balls lubed.

 

[BILT4ME]

Is this something I can do without taking the knuckle apart?

Yes.

I had the same issue when I rebuilt my front axle.

I put it all together, followed the FSM line by line, and 1500 miles later, it was leaking oil all over and I had Birf Soup.

I pulled the fitting off the back of the axle housing and I had to use a drill bit to clean out the hardened goo in it from the PO never servicing it.

The factory vent is not really "serviceable". I have since actually removed it completely and it is still sitting in my parts washer.

I used (3) hose clamps, 5 ft of 1/4" fuel line, attached the bottom end to the fitting with a clamp, routed it up the left side of the engine where it won't get pinched (make sure to leave enough slack for suspension droop) then lopped it over my brake booster and bought a squeeze clamp -and screwed it to the firewall by the booster. Then installed the 1/4" fuel filter (keep that in the vertical up side of the combo) then turn the tip of the hose back down for about 8-12"

After I put this on, my birf soup stopped and a number of folks on here thought I was full of shyt, but there have been others now that have corroborated this process. I've done another 130K miles since then, but now I have birf soup because I have that many miles on the rebuild.

 

[Kernal]

@TheMindofJ : Also, smell your balls, or (easier) swipe a finger on the wet area and check the odor, gear oil has a very pungent smell much different than grease, engine oil, etc.

If you knocked the garter spring off the axle seal during installation or damaged the seal, that might explain a leak; have you looked into the inspection port on the top of the knuckle? Stick a screw driver into the hole and pull it back out; what does it smell like??

On top of everything already said, oil from the grease (or gear oil if present) can work it's way down inside the threads of the steering knuckle studs and drip off the ends of the studs/nuts.

FWIW, to prevent that type of seepage I use thread locker on the studs when installing a new set but also put a plug of FIPG on the inside top of the stud holes which are open into the knuckle cavity. Added the FIPG after the studs were installed into the knuckles while it was all apart, squeaky clean and dry on the bench before reassembly.

 

[TheMindofJ]

all noted. Looks like I gotta sit down and plan my attack. Good thing is I’m doing a cooking system flush right now so no miles are being put on my balls. Thanks boys I’ll follow up in a few weeks when I’ve made some progress

 

[Malleus]

Cooking your balls?

 

[mudgudgeon]

Y'all need help!!

"Honey,
I've been in the garage lubing my shaft. Then I checked my nuts and lubed my balls too.
The guys said if my balls are wet, wipe my finger across my balls and smell it.
I'm not sure?!
Does this smell like soup to you?
I might need you to help me with a knuckle job later . . . . "


When @TheMindofJ came to a couple of hours later, his garage and cruiser were a smouldering pile of ashes, the furniture was all gone, and so was his wife!



What happens in the garage stays in the garage!

 

[SpenserAK]

Y'all need help!!

"Honey,
I've been in the garage lubing my shaft. Then I checked my nuts and lubed my balls too.
The guys said if my balls are wet, wipe my finger across my balls and smell it.
I'm not sure?!
Does this smell like soup to you?
I might need you to help me with a knuckle job later . . . . "


When @TheMindofJ came to a couple of hours later, his garage and cruiser were a smouldering pile of ashes, the furniture was all gone, and so was his wife!



What happens in the garage stays in the garage!

This post alone should be a sticky

Not to be confused with sticky balls

 

[TheMindofJ]

Ok. So it’s been a few weeks and I haven’t had time to work on my Land Cruiser. Here is an updated picture from this morning… any updated opinions on what this leak could be? Now that it’s more visible?