Big Differential Sucking Sound

[MDJEEPER]

So, I was about to dig into my front and rear diffs to change out the fluid...then I got to thinking to myself..."Self," I said, "why can't I just suck the old gear oil out of the diffs using the filler plug holes?"

I can think of two main advantages to replacing the fluid this way....(1) I don't have to deal with those 22 rusty, crusty bolts holding the front and rear diff covers on, and (2) right now, my diffs are absolutely bone dry in terms of leakage from the seals, so why disturb them?

The big disadvantage I can think of doing the fluid change this way is that I won't be able to inspect the axle gears...but then I don't have any indications of problems. I suppose I also might not be able to get all of the fluid out?

Has anybody changed their diff fluid this way??

 

[Old Dog]

I like to take the covers off. That way I can see whats going on in there.
I've never had any trouble sealing them back up with a little rtv.

 

[IOPort51]

Taking the cover off gives you the opportunity to put your hand in the gear oil that is left in the bottom and feel for shrapnel. One tiny chip of high carbon tempered steel run repeatedly through the R&P will cause things to become "unputtogether" in a very short time. If you find such a chip in the bottom of the housing, you may be able to save things with a thorough cleaning or start saving for the new differential and R&P. Also If you have made a milkshake in the axle you will need to drain, clean, wipe down, ETC.

 

[TDHofstetter]

I agree with the guys, for sure - yank them covers off & clean out the housings really well. Inspect your rags after cleaning, looking for shards & such, bottle caps & hypodermic syringes glinting in the sun. Ahem. Metal. Shavings, powder, bits, hunks, half-a-battleships.

Also look closely at the wear patterns on the ring gear t'see if it wants attention.

Sucking it out, you'll never get it all. RAGGING it out, you can.

 

[Sasquach]

I just did my front yesterday and as said above you really want to get ALL the oil and sludge out and off the bottom of case.