Birf grease in the diff

[hammerheadfistpunch]

So I keep getting birf grease in my front diff. My trunions aren't being affected except to say that they go through grease really fast (i.e. no birf soup) the breather line is clear and um...breathing. Bad seals? Not sure what the story is with sucking in birf grease into the diff. Also, how is the pinion bearing lubricated? because I suspect its not loving this soup if its from the gear oil.

 

[Golgo13]

I really don't think you have anything to worry about with birf grease getting into the gear oil. The differential bearings need lube; whether it is birf grease or gear oil or a mixture doesn't really matter. My concern would be pulling water into the knuckle through the wiper seals. If you don't have that issue, I wouldn't worry about it. I would much rather have the grease flowing that direction instead of having the oil leak out the other way.

 

[hammerheadfistpunch]

I really don't think you have anything to worry about with birf grease getting into the gear oil. The differential bearings need lube; whether it is birf grease or gear oil or a mixture doesn't really matter. My concern would be pulling water into the knuckle through the wiper seals. If you don't have that issue, I wouldn't worry about it. I would much rather have the grease flowing that direction instead of having the oil leak out the other way.

The trouble is 2 fold:
1. its a lot of grease, like I changed it last night and globs came out
2. The front is getting louder. its got nitro 4.56 up front and people keep telling me its supposed to make noise but I think the pinion bearing is going bad from the sounds of it...or the gears weren't set up right and are just beating themselves up.

The wiper seals are new and inspection of the trunions has revealed no water so we're good there.

 

[Funner]

Is it possible you are forcing too much grease into the birf through the inspection port?

 

[hammerheadfistpunch]

Is it possible you are forcing too much grease into the birf through the inspection port?

possible, I fill up em but I can't say I jam them full. Either way, the grease in the DS side especially dries up pretty quickly. like 6 months from full to gone.

 

[Tools R Us]

How long was the gear oil run before changing? It's somewhat normal, the knuckles don't have breathers, so there is always some migration. The front axle lube needs to be changed more often than most axle types.

 

[Tools R Us]

possible, I fill up em but I can't say I jam them full. Either way, the grease in the DS side especially dries up pretty quickly. like 6 months from full to gone.

They should never be full, there has to be air space, or it will quickly be pushed into the axle. Best to maintain it at ~1/2-3/4 full.

 

[hammerheadfistpunch]

They should never be full, there has to be air space, or it will quickly be pushed into the axle. Best to maintain it at ~1/2-3/4 full.

I never fill them 100%, more like 3/4.

 

[hammerheadfistpunch]

How long was the gear oil run before changing? It's somewhat normal, the knuckles don't have breathers, so there is always some migration. The front axle lube needs to be changed more often than most axle types.

I change the front fluid every 5000-10000 miles or so

 

[hawaiicruz]

Do you have your caster corrected after lift? If not that puts the pinion bearing higher than normal which may cause insufficient gear oil to that area. FYI I have 5" lift and no caster correction, and no problem with the pinion bearing after thousands of miles. I also drove thousands of miles with birf soup before I rebuilt my axle, with no ill effects. As always YMMV
Enjoy your posts over on Kinja keep it up

 

[hammerheadfistpunch]

Do you have your caster corrected after lift? If not that puts the pinion bearing higher than normal which may cause insufficient gear oil to that area. FYI I have 5" lift and no caster correction, and no problem with the pinion bearing after thousands of miles. I also drove thousands of miles with birf soup before I rebuilt my axle, with no ill effects. As always YMMV
Enjoy your posts over on Kinja keep it up

I do have the castor correction, so I don't think its play. Thanks on the kinja bit, Enjoying it.

 

[Funner]

Well if everything is rebuilt, all the fluids are filled to the correct levels and you are

possible, I fill up em but I can't say I jam them full. Either way, the grease in the DS side especially dries up pretty quickly. like 6 months from full to gone.

Is this a daily driver, how many miles in 6 months?

 

[hammerheadfistpunch]

Well if everything is rebuilt, all the fluids are filled to the correct levels and you are


Is this a daily driver, how many miles in 6 months?

daily driver, 12,000 a year. so 6000 miles or so. the axles were rebuilt 20,000 miles ago.