Since I bought my Blazer one year ago the only preventive maintenance I have not done is changing the fluids in both differentials and the transfer case. Yesterday I changed the gear oil in both differentials. Chose to use mobil 1 LS 75w-90 in them. Then when I got to the transfer case. It said to use dexron III or auto-trak II. Which one? Where do I get it? According to my Haynes manual there is 3 choices in transfer cases, 133/136, 233, or a 236/246. All have different fluid capacities, how do a tell what type I have?

 

If you have the 4 button then it takes the auto trak 2, very expensive stuff. If its the 3 button then just dexron 3.

 

So I have four button. 2hi,4lo,4 hi, and auto four wheel drive button. When I changed front diff oil, I noticed it was leaking.so I cleaned the underside of blazer spotless. I seen that it has a small leak where the driver side cv axle mates to it and also the seal is leaking where the shaft from transfer case enters the front diff. Even though they are not bad leaks, I'm going to have to fix them. Anybody else discover this nightmare on there vehicle ?

 

I've replaced those seals on my jimmy and my father in laws blazer. They seem to be pretty common. Its not too bad of a job, just take your time. Be prepared for some sticker shock on the auto trac fluid, last time I looked it was almost 30 bucks a quart.

 

The Auto Trak fluid is like 8.95 a qt (litre) actually at the dealership.

Or got to summit here is a link http://www.summitracing.com/parts/NAL-88900402/

 

The fluid at summit is GM. After shipping you only save a couple bucks.

If you live a ways from a GM dealership it is a viable option.

I got three 33.8 oz bottles for under 28.00 including shipping