getting the diff oil out

[mac495]

vetters

I have a 1981 and correct me if I'm wrong but the only way to get the old diff oil out is to pump it out through the fill hole...My question is has anyone tried to put a drain plug in or is it even possible..

thanks

 

[Yoda]

Hey Bill,

I think there is even a small kit for doing it. I've always been kind of afraid of getting some of the drill filings caught inside the pumpkin :eek . Quite some time ago there was someone here at CAC that did it and I believe several others followed suite.

The Chevrolet garage here in Modesto will change the fluid in the rear end and add the GM posi-additive for $24.95 or so. Plus it give me a chance to walk around under the ole girl and see how she is holding up

 

[mac495]

BudD

Right on thanks I knew there had to be a kit to do it..I try to stay away from places like GM dealers, because there are things like the catalytic converter that just fell off (if you know what I mean)

 

[rainman]

I think that there was an article in Corvette Fever or one of the other mags about a year or so ago that described how to put a drain plug in the dif.

 

[80convertible]

I try to perform most of the service work myself, but the diff oil change was an exception. I did take it to the chevy dealer who charged me about $50.00 to drain, refill and add 2 bottles of posi-additive. If you dont' break the cover you have to suck it out. The dealer had the right tool to get way down in the diff and suck out the real crud. I have to pull the diff the summer to replace a worn side yoke, so maybe that will be a good time to install a drain.

 

[Bob Chadwick]

I was just looking at the pumps at NAPA as I overfilled the power steering unit and had to remove some fluid. I think I paid $10 for a pump that pulls out either a pint or a quart with each stroke. Seems to pretty good quaility.

 

[Robin7TFour]

BOB, as for the p/s overfill. a turkey baster and a bit of hose will do fine to suck out the extra in the p/s res.
also, harbor freight usually has good deals on pumps.

my 02

ROBIN

 

[redvet]

Diff Oil Change

You can buy a device specifically made for this purpose. It looks like a grease gun, but with a clear plastic hose atached to one end, and a "pull handle" on the other end. You will find them available in most auto parts stores. Remove the fill plug, insert the hose, pull the handle and suck all the old oil out. It works quite well, I just did this on my 82. I suggest you also do what I did; as somewhat of an assurance that I got most/all of the old oil out, I measured what I took out and compared it to the spec for the amount the diff is supposed to hold. It was very close, so I felt comfortable using this method.

One more thing: upon refilling the diff, make absolutely sure you add two bottles of the GM limited slip axle additive. You can get it at any GM dealer. I absolutely recommend ONLY the GM stuff, and TWO, not one, bottles. All sorts of problems if you don't!

 

[Barry08]

If your gonna do it..... do it right!

Sucking out the lube will not remove the filings!!!!



Barry

 

[Stallion]

Oh man, that's a bigger job than I thought it would be. I was going to do this next on the list after the clutch.

 

[Bob Chadwick]

BOB, as for the p/s overfill. a turkey baster and a bit of hose will do fine to suck out the extra in the p/s res.
also, harbor freight usually has good deals on pumps.

my 02

ROBIN

You know Robin I figured that out after I bought the pump. :L Needed it anyway for the posi change coming up shortly.

 

[Dave L.]

Another tip: Before using the suction gun to remove the oil, remove the spare tire assy(gives you more room under there) and then drive the car around the block several times to warm up the oil. The warm oil removes much easier.