8 3/4 axle lube change

[dartley]

My axle lube is at the proper level, but it's been in there for I have no idea how long, and one thing troubles me some - the last time I went to check the level, cold, when I took the plug out it was under a very slight amount of pressure, and I felt a wee bit of air escape from it.

So I figure I might change the fluid. I have three Qs:

1) If I want to just add some Mopar limited slip lube, can I do so w/o changing the fluid?

2) If I change the fluid, do I need to get it all out (the 8.75", as you know, requires a turkey baster thingy to get the earl out.

3) What about that pressure I mentioned ... is that normal, or does it indicate a problem?

Thanks folks,

 

[Ace]

I'd recommend removing and cleaning the vent found in the brass distribution block the brake lines go through. Should be bolted on top of the driver side housing. I'd also change the oil if you don't know how long it's been in there. An easy way to drain it completely is loosen the bolts holding the center section and use a jack to press up on the pinion yoke. That will crack it open enough to drain and it should re-seal by just tightening it up again if the gasket is not damaged. I've done three like this and never had a leak afterwards.

 

[longarm]

most oil change facilties can draw out the lube
through the fill hole.
they can't get 100% out, but most.
add your additives then refill.
check & clean the vent as Ace suggested.
where i live it costs 10 bucks + additives.
good luck,
longarm

 

[dartley]

Thanks. When you say remove the vent, you mean - duh - taking it off the car and soaking it, right ... not just loosening it? Well it's about time to replace the brake fluid too anyway.

 

[krabysniper]

The vent is basicly a bolt with a hole drilled thru it and has a tin cap with rubber seal inside pressed on top to keep dirt and crap out. It allows for expansion of the fluid in the rear housing. They can get crusted with dirt and crap and then not function the way they were meant to causing axle seals to fail or seap. One word of caution when working on it, DO NOT over tighten it when putting it back in, it can/may break very easily and then good luck finding a new one. I had a buddy helping me with my car a while back and he was putting the vent back in and broke the damn thing, I ended up tig welding the two pieces back together because I was unable to locate one localy.

 

[dartley]

Thank you sir.