Procedure for changing diff fluid?

[AlabamaDan]

Here's a great link about this:

http://www.4x4xplor.com/diff-service.html

 

[dspilot]

Also, buy a pump. I did not, and had to get really creative to get the oil back into the diff. Woulda been eight bucks well spent.

 

[dj's 2000 xj]

Also, buy a pump. I did not, and had to get really creative to get the oil back into the diff. Woulda been eight bucks well spent.

Big syringe and hose. Sucks and pumps eace:

 

[Begster]

I don't know about you guys, but I have heard on a couple other sites not to use a screw driver or anything to pry, because you could end up scratching up the mating surface, so that it could potentially have ill effects for sealing the cover later on. When I change my fluid I follow those directions up until the part where you take loosen the top bolt but leave it in. I then use a rubber mallet and hit the cover on the side to break the seal. http://jeephorizons.com/tech/diffoil.html

For sealing it up, I use gray RVT. My offroad shop uses that on all the ones they do, as well as my previous car shop.

At autozone they have a long hose that screws onto the diff fluid bottle, and you can open and close it, I used it and it worked pretty well. The pictures in the link I posted also use this same thing.

As for the post that says learn to love the smell of gear oil. I changed the gear oil on my d30 when I had it off, previous owner probably never changed it, and it smelt pretty burnt. I was doing the work in my friends garage, and he decided to leave the old oil in there. That garage reeked of the gear oil for at least a month, even after it was moved. Smelt horrible.

 

[Speed_racer]

Razorblade.

Keep scoring it, over and over and over... yes, and OVER!! eventually you will get between the metal..

Also, smack around it with a rubber mallet... not too hard obviously...

Once you get the razorblade edge in, keep scoring it around the edges...

Then find a long skinny flathead... tap it in , move an inch or so... tap it in, ... repeat...

and I use the black GREAT STUFF to put mine back together...

 

[Myles]

here's a pretty good write-up for you...


http://www.4x4xplor.com/diff-service.html

 

[Bradlybob]

Just be careful when using sharp razor knives and such for trying to seperate things. I think I've cut all of the fingers on my left hand at least once, which explains the bandage I currently sport on my middle finger.

 

[fubar XJ]

I use a stiff, sharp scraper to seperate the cover from the diff. Simply orient it between the two surfaces and tap (don't beat) it in with a hammer, working around the circumference as you go. It will go further in each time you go around until it breaks the seal. Make sure your scraper is sharp (take it to the grinding wheel) and has no uneven dings on the edge that would score the diff mating surface.

 

[tommyr]

Make sure your scraper is sharp (take it to the grinding wheel) and has no uneven dings on the edge that would score the diff mating surface.

This is one reason to use an RTV type sealant instead of a paper style gasket.
RTV can fill up little scratches on the mating surface. To clean the cover and diff, I use a small air angle grinder with a 'scotchbrite' type pad on it to remove old RTV, then follow that up with a paper towel with brake cleaner sprayed on it. Surfaces are nice and clean/shiny. Last thing you want is to pull the cover again because it is leaking a little.....

 

[rcnerd]

If you use something plastic you can be pretty reckless and not have to worry about being careful....

 

[scorpio_vette]

I HATE RTV with a passion. i don't use anything but gaskets. they're a couple bucks at the parts store, and make for a much cleaner and easier install/removal.

as far as getting the diffs off. ever since i started working on cars, i just use a decent rubber mallet and wack at both sides of the diff cover back and forth until it breaks the seal. make sure you leave the top bolt in loosely, so the cover doesn't go flying when it breaks the seal. i've been doing that for years, and so do most of the guys at the shops i've worked at. the only diff cover that i've ever encountered that didn't like being hit was a AMC 20 axle. those diff covers are as thin as paper.

then i use one of those wire wheels on a bench grinder to wire wheel the diff cover surface nice and clean and shiney. for the surface on the diff i use a air grinder with a soft abbrasive cleaning pad (NOT A HEAVY SANDING OR GRINDING PAD). a couple seconds with that, and the surface of the diff is nice and clean. then a good cleaning with brake cleaner, and i just hold the new gasket against the diff cover and place it against the diff.

after you have everything tightened down and cleaned and perfectly dry, you can see if you happen to have some extra cans of flat black spray paint laying around, and spray the diff while you're at it. now it looks just like new. lol

 

[fubar XJ]

I HATE RTV with a passion. i don't use anything but gaskets. they're a couple bucks at the parts store, and make for a much cleaner and easier install/removal.

as far as getting the diffs off. ever since i started working on cars, i just use a decent rubber mallet and wack at both sides of the diff cover back and forth until it breaks the seal. make sure you leave the top bolt in loosely, so the cover doesn't go flying when it breaks the seal. i've been doing that for years, and so do most of the guys at the shops i've worked at. the only diff cover that i've ever encountered that didn't like being hit was a AMC 20 axle. those diff covers are as thin as paper.

then i use one of those wire wheels on a bench grinder to wire wheel the diff cover surface nice and clean and shiney. for the surface on the diff i use a air grinder with a soft abbrasive cleaning pad (NOT A HEAVY SANDING OR GRINDING PAD). a couple seconds with that, and the surface of the diff is nice and clean. then a good cleaning with brake cleaner, and i just hold the new gasket against the diff cover and place it against the diff.

after you have everything tightened down and cleaned and perfectly dry, you can see if you happen to have some extra cans of flat black spray paint laying around, and spray the diff while you're at it. now it looks just like new. lol

Gaskets are nice, a tube of RTV is usually more convenient, not being application specific. I also love having access to a bench wire wheel and similar air grinder to clean the surfaces. The last one I did was in a parking lot of a buddy's apartment, had to scrape/solvent clean both surfaces. Much more labor intensive.