04 XL Differential Fluid Change

[networkman]

Hey all,

I have an 04 XL 2WD that I need to change my differential fluid on. Unlike my diesel which is easy to change all fluids, I don't see where to drain or fill the fluid on the Yukon. From my reading, it looks like I just loosen all of the bolts and let the muck drain out. After that, I can take the cover off and clean it.

1. Once the muck drains out, what can I use to clean the rest of the bad fluid and muck out? 2. What do you recommend for a gasket or sealant when I put the differential cover back on? 3. Where is the fill point to add the new differential fluid? Any other advise?

 

[dougk109]

I just did mine, a 2001. Not sure if they are the same or not, cant imagine why not. There is a plug on the bottom of the diff, a 3\8 drive ratchet and small extension is all that was needed to take plug out. Then on the right side twords the top is a same sized plug that you fill the diff up to. Look and see if there is a tag that says about having the level a measured depth BELOW the hole. If you fill the diff the old way, up to the bottom of the hole, the axle seals WILL leak. For the measured distance down, I took a piece of copper wire and cut small notches in it and kept sticking it in the hole while checking the level as I was filling it. You dont have to take the cover off at all that way. I did take mine off though because I put new axle seals in while I was there. You want to be real sure the cover is in good shape putting that expensive oil in there, they are known for rusting out!! I just used silicone when putting the cover back on with no probs.

 

[Splatmaster527]

The post above is good but I want to clear a few things up...

The FRONT diff has a drain and fill plug. All you do is drain it and fill it back up to about 1/2" from the bottom of the hole with 80W-90. If you use a small allen wrench as a gauge that makes things pretty easy. The 1/2" isnt too crucial just make sure its full.

The REAR diff has no drain hole and you will want to completely remove the cover so you can get the metal shavings and such off the magnet in there. You can use a rag to get most of the sludge/gunk out. Then use some Permatex Ultra Black RTV Silicone to seal up the cover and replace it. Then fill the diff with 75W-90 to between 5/8"-1 5/8" from the hole. Same allen wrench trick.

 

[OmarR]

2002 and earlier will have a drain plug on the rear diff.

Bending a long zip tie to the appropriate length is easier to hold on to than an alllen wrench.

 

[ScottyBoy]

This reminds me, I need to replace the diff oil in my 01. Fail on my part since I have had the drinking grant oil sitting here since about March. Almost a whole year now. Lol!