Differential Cover

HaroldCallahan · April 21, 2005

I would like to change the differential fluid in my wife's 2005 Yukon XL. It looks like the crossmember and sway bar are in the way of taking the cover off. It looks like it might clear if the rear of vehicle is raised. Does anybody know if the cover can be removed and replaced without unbolting, moving or removing the crossmember/sway bar ???

My old '88 GMC Suburban is a lot easier to work on than this new Yukon.

Also what is a good mileage for the first differential fluid change ? I have heard that an early change to get out any metal debris etc will extend the life of the differential considerably.

Also what is a good fluid to use ?

MS3DALE · April 21, 2005

I always change my diff. fluid for the first time at 3,000 miles and then about every 15,000 miles after that.

As far as fluid goes I use the GM stuff only (part#89021677),but any good 75W-90 synthetic gear lube will be fine,DO NOT add any additives or friction modifiers,These rear ends in these trucks do not require them and I've seen some cases where guys added them and ruined there rear diffs!

As far as removing the crossmember/sway bar or not I cannot help you there as all of my trucks have been pickups and they don't have them.

snoman · April 21, 2005

I would like to change the differential fluid in my wife's 2005 Yukon XL. It looks like the crossmember and sway bar are in the way of taking the cover off. It looks like it might clear if the rear of vehicle is raised. Does anybody know if the cover can be removed and replaced without unbolting, moving or removing the crossmember/sway bar ???

My old '88 GMC Suburban is a lot easier to work on than this new Yukon.

Also what is a good mileage for the first differential fluid change ? I have heard that an early change to get out any metal debris etc will extend the life of the differential considerably.

Also what is a good fluid to use ?

<{POST_SNAPBACK}>

There is no need to remove the cover fully. You only need to loosen the bolts enough to allow cover to break loose from seal and let the oil run out and there is enough clearance for that. I never take my cover "off" as I only loosen the bolts enough to drain then retighten them.

100R1 · April 21, 2005

You do not need to remove the cover to drain & re-fill

there are plugs on the front side of the pumpkin taht you can use to drain

to make life easier in removing the cover, raise the rear of the vehicle and support on stands, lket the axle "hang" until the rear tires just touch the ground, this will allow the cover to drop below the rae sway bar etc.

It is a good idea to remove the rear cover on the first fluid change to check the magnet for metal particles and to check all of the teeth for proper breakin. After the first change you can go every 2 - 3 changes with only a fluid change.

If you tow or abuse your vehicle (off road fun) I would check (remove diff. covers) more Freq.

Redline makes a good synthetic fluid for the axle.

MS3DALE · April 21, 2005

No drain plugs anymore on the 1500's (for the rear ends and tranny pans).They took them out sometime in the '01-'02 model year,another "cost saving" feature from GM!

I think the HD's still have them.

100R1 · April 21, 2005

No drain plugs anymore on the 1500's (for the rear ends and tranny pans).They took them out sometime in the '01-'02 model year,another "cost saving" feature from GM!
I think the HD's still have them.

<{POST_SNAPBACK}>

I have them on my '01 yukon (1500 series)

d**n, I really like the drain plugs!... .....

What's next ?

Well then ya got to jack up the rear end and let it hang down to clear the rear sway bar.

Oh yea, dont use a screw driver or pry bar and try to force it between the cover & housing, you could gouge or bend the cover and have a leak when you go to seal her back up.

Use a rubber mallet & tap on the cover.

snoman · April 21, 2005

No drain plugs anymore on the 1500's (for the rear ends and tranny pans).They took them out sometime in the '01-'02 model year,another "cost saving" feature from GM!
I think the HD's still have them.

<{POST_SNAPBACK}>

I have them on my '01 yukon (1500 series)

d**n, I really like the drain plugs!... .....

What's next ?

Well then ya got to jack up the rear end and let it hang down to clear the rear sway bar.

Oh yea, dont use a screw driver or pry bar and try to force it between the cover & housing, you could gouge or bend the cover and have a leak when you go to seal her back up.

Use a rubber mallet & tap on the cover.

<{POST_SNAPBACK}>

You can use a wide blade screwdriver as long has you only pry between case and cover lip. I do it all the time and have done it for years with no leaks either afterward. You just do not want to drive it in there to break it lose and possible damage seal.

HaroldCallahan · April 22, 2005

Thanks for replies.

No drain plugs on this '05 Yukon.

I usually put a new gasket (but not always) in when I remove the cover on my other vehicles like for instance the old Suburban. This is the first truck/suv that I have owned that had anything in the way.

Hopefully jacking up the rear will enable me to get the cover off completely, or at least have enough clearance to get to the magnet and put a new gasket in if the original gets damaged.

There is no magnet in the old 1988 GMC burbs 10 bolt, maybe there was one at one time and somebody didnt put it back in ???

As far as the magnet goes on the new Yukon, is it removeable and where is it ?

Without looking real close the cover looks just like the 10 bolt on my old 1988. Is the gasket the same ?

What gasket should I get so that I dont end up with the cover removed and a damaged gasket and no replacement ?

Thank for the help !!!

MS3DALE · April 22, 2005

The gasket is the same as on your '88 1500,GM part #26066456

The magnet on the 1500's is mounted right on the cover itself (right where the little "dimple" is)On some rear ends its just sitting on the bottom of the axle housing itself.

Sometimes its just mounted with the magnetic force and sometimes GM uses a little silicone to hold it in place (as mine is)