big jimmy

Why would my front diff breather tube suddenly belch fluid?


I have Amsoil fluid in there and it was filled to a bit below the hole.

Any ideas?

Jimmy

infidel

Haven't figured out what the combination of circumstances it takes to make them puke but most all do it once in while. I wouldn't worry about it.

BTW the correct oil level is 3/4" below the bottom of the fill hole. I've seen quite few start leaking out the axle seals when overfull.

ratsun

Over the course of 2 months I have towed the same load the same route 6 times and two times ago it did it to me too? Go figure? I thought I had a problem but it hasent done it since?

big jimmy

I'd like to know if it has anything to do with the breather malfunctioning, which is a very cheap plastic thing.

ratsun

I wish I could tell you but???????????
I hope some one can shed some light on this.

infidel

Theory only-
I think what it takes is getting on a tilt that allows a little oil in the breather line. Oil doesn't come out till much later when the differential gets hot enough to vent thus pushing the oil out.

MDMIKE

Not to hijack, but if the fluid is leaking out of the axle seal when its too full, does this neccessarily mean the seal is bad? After my front gear install, my drivers side will leak until it gets about 1/2" down from the fill hole and then it stops (from what I can see). I've been stubbornly filling it back up to the bottom of the hole again, watching it spew out all over the inside of my wheel/inner fender/ then refilling. Just waiting to get time to get in there and fix it since its pretty much a complete disasembly of the front axle to get to it. If I haven't done any damage to the seal, I think I'm gonna let it stay where it is! Back to your regularly scheduled thread

MIke

waldersha

This is exactly what Infidel is talking about. If it is filled to the hole, the fluid may get past the seal. If it stops leaking 1/2 to 3/4" down from the hole that is the way it should act. Your seals are probably fine. Just keep an eye on your fluid levels. Your brakes will also tell you if you have a leak.

big jimmy

I could buy that, considering some of the places I drive in the Rockies. That and a slightly overfull pumpkin.

Jimmy

infidel

I can't count the number of rigs bought to me with a leaking seals that were cured by dropping the fluid to the correct level. It has worked on every single one.
In fact I've had a replacement seal in my glove box for over 150k that I never had to use once the oil level was correct.

It may take several hundred miles for the oil to quit coming out as it's trapped in the axle tube on the wheel side of the seal. You can speed up how long it takes to finally drain by parking your truck tilted towards the leak.

What's funny is factory service manual doesn't mention the correct level but the owner's manual does.

Somewhere along the line, guessing about '99, the specs were changed to fill to the bottom of the hole. I think all they did is lower the fill hole on the cover.

MDMIKE

You're the man Infidel! I'll keep an eye on it, but it looks like you just saved me at least a half day's work! Thanks!

MIke