Recently I had been experiencing a shudder in tight turns on clean dry pavement (ie my driveway). So I decided to change out the transfer case fluid last night. The process went fairly straight forward. I had forgotten to pick up the small hand pump from my dad to get the new fluid in, but I just used my air compressor to pressurize the bottle with a hose from the bottle of GM Autotrak II fluid to the fill port on the case. It took a little extra time, but worked none-the-less.

GM Autotrak II fluid should be used on any AWD and Auto4WD transfer case. All others can use regular ATF transmission fluid.

I must say that the results are better than expected. Just driving it today, it was like I had done a miracle (ok maybe not a miracle...). I had been getting a slight stumble when driving down the road. Now this stumble is something that my wife never EVER notices and swears that I'm going crazy, but I can feel it. It is now pretty much gone since I changed the fluid. The shudder at slow speeds while turning is also gone. I would have thought that this would be something that would take some time to counter act the effects of old/degraded fluid, but I am very surprised to say that it was a pretty much instantaneous change in the symptoms.

The old fluid came out noticeably darker and smelling slightly stronger than the new fluid that went in, but it didn't look horrible by any means. I have to assume that this was the first time since the truck was new that this service has been done seeing as how the drain plugs still had the factory applied sealant on the exposed threads.

Now it's on to at least checking the front diff oil level. The front axle was rebuilt just after I purchased it because it had been run dry. I just want to check it and maybe change the oil while I'm under there. We'll see how much gear lube I have in the garage! LOL

 

i noticed mine did the same thing on dry pavement, or is mine supposed to in 4 wheel?
the only reason it was on the dry pavement is cuz i was just getting ready to go thru a big mud hole and i had to turn around. Also how do you/where do you check the transfer case and front diff. fluids?

 

If you have auto4wd, it may rock a bit (very slightly) in auto4hi/4hi/4lo, but shouldn't at all in 2hi. If you have part-time 4wd (ie no auto option), then it will do it in 4hi & 4lo much more than the auto4wd or awd vehicles will do.

As far as checking TC and frond diff fluid levels, there are plugs on the sides of the cases. The TC is pointing straight back and is on the drivers side of the case. And I haven't looked at my front diff close enough to definitively say where it is, but it's there.