T-case and front diff service

[Buck]

The fluid I got out of my T-case was a medium brown color(motor oil color)? What does GM put in the T-cases? Some kind of additive or do I have bigger problems? I put in Mobil 1 ATF.

Front diff was full of green crap with sludge/metal shavings globbed on the magnetic plug. I put in Mobil 1 75W-90 gear lube.

Any comments?

[jbplock]

Buck,

The Transfer case on the 2500HD/3500HD's use Dexron III ATF. Since yours was brown it would seem like the transfer case had been worked hard. Do you use your 4WD often? I drained mine at about 5kmiles and it was still red but I don't use my 4WD very often. I also refilled with M-1 ATF.

Like yours my front diff plug also had sludge on it. Did yours look like this?

Front Diff plug at 5 kmiles:
http://community.webshots.com/s/image5/8/48/24/65684824eVapur_ph.jpg

more Diff plug pics (http://community.webshots.com/album/65684589edLUNA)

I refilled the front diff with M-1 75W-90. I checked it recently at with 19k miles on the lube and it looked like new.

smile.gif

[Buck]

I use it a lot in the winter, not very often the rest of the year. This was my first lube change on diff/t-case. I have 55000 miles on my truck now, just over 2 years old. I figured that I had close to 500 miles in 4wd so I changed them.

My front diff plug looked like yours.

[JimWilson]

The ATF I drained from my tcase was still pretty red, but the truck only had about 5K on it so I would certain hope it still looked good. I replaced it with Mobil 1 too.

The sludge that came out of the front diff at 5K shocked the heck out of me. It almost looked like it had been contaminated with water. It stunk too. And, as with the rest of my truck, Mobil 1 went back in their as well.