96 Yukon front diff and Xfer case fluids

[JDD]

I know--I know, RTFM!! Well, those pages are missing from my ownwers manual. I need to know what fluids go in the front diff and transfer case, and what is/are your recommendations for a 1996 GMC Yukon. Has the push button 4 wheel drive. I prefer semi synthetics or a good quality dino. I heard that the xfer case in the push button 4X4 needs special fluid. Yes or no? Your input is appreciated as always---

 

[Turk]

Amsoil Severe Gear 75-90 in the Diff.

GM Auto-Trak II in the X-fer case.

 

[jstutz]

You can have a push button 4wd without needing special autotrak2. It is the transfer cases that have the auto 4wd that you must use the autotrak 2. I just had a front xfer case bearing go out on my xfer case and mech found red transmission fluid instead of auto trak. I bought the truck used so i didnt get to checking it. As far as the front diff, basically take your pick. Book calls for any GL-5 fluid. I personally like to change my front diff regularly becuase condensation tends to build up in there. Probably becuase i never use it so it never gets warm. As mentioned above Amsoil makes a great product and Valvoline durablend is spoken highly of. FWIW i have used mobil 75w90 in my 01 blazer for 181k miles, changed every 30 to 50k miles, in the diffs and they are still going strong. Good luck

 

[JDD]

Originally Posted By: jstutz
You can have a push button 4wd without needing special autotrak2. It is the transfer cases that have the auto 4wd that you must use the autotrak 2. I just had a front xfer case bearing go out on my xfer case and mech found red transmission fluid instead of auto trak. I bought the truck used so i didnt get to checking it. As far as the front diff, basically take your pick. Book calls for any GL-5 fluid. I personally like to change my front diff regularly becuase condensation tends to build up in there. Probably becuase i never use it so it never gets warm. As mentioned above Amsoil makes a great product and Valvoline durablend is spoken highly of. FWIW i have used mobil 75w90 in my 01 blazer for 181k miles, changed every 30 to 50k miles, in the diffs and they are still going strong. Good luck


Don't think it's the auto 4WD, but not 100% sure. Going to pull the diff codes from the glove box and see what it says.

 

[Boomer]

Inj my 97 Chev PU 4WD, I used Mobil 1 ATF in the transfer case and Mobil 1 75W-90 in both diffs. No problems.

 

[jstutz]

It is very easy to know. On the pannel where you choose 2H, 4H, 4L. If it is the auto 4wd there will be an extra button on that pannel that says Auto 4wd. If you only have the first three options, then its not auto and you can use dex 3, dex 6 or M1 in transfer case. If your not sure you can use the auto trak 2, it just is not necessary is it isnt auto.

 

[JDD]

Originally Posted By: jstutz
It is very easy to know. On the pannel where you choose 2H, 4H, 4L. If it is the auto 4wd there will be an extra button on that pannel that says Auto 4wd. If you only have the first three options, then its not auto and you can use dex 3, dex 6 or M1 in transfer case. If your not sure you can use the auto trak 2, it just is not necessary is it isnt auto.


Nope, no extra button, so I don't need the special fluid. Thx to all who helped out. Can always count on Bitogers.

 

[JDD]

But is the rear diff limited slip? How do I tell?

 

[Herz]

GM recommends 75-90 fully synthetic. I use valvoline.

 

[jstutz]

I dont think you can tell just from looking at the outside. Personally i would drain it and fill it with synthetic, 75w90, Use Amsoil, valvoline, or M1. They already have the friction mods to accomidate the LS. I have been using the M1 and never needed to add the gm friction modifier. when i used dino valvoline 80w90, the rear end would chatter when making sharp turns on the pavement.