So i’m almost home (15 miles?) on a 650 mile day when the transfer case in the Suburban (2004 6.0 2500 model) starts making a god awful squealing noise. I pull in to autozone and get a quart of gear oil. I pumped it into the TC and was about to get more and went online to see how much it needed and saw that everyone online recommended some unicorn tears, dealer only ATF.
So am I boned? What do I do?
If it has a shifter on the floor, don't worry.
It's an auto transfer case, drain it and use the right stuff. It has an oil pump that actuates clutches when in auto mode.
If you have push buttons but there is no "automatic" option, you probably won't hurt anything with gear oil, not ideal.
No matter what, godawful squealing noises aren't great. I wouldn't bother diagnosing it any further than seeing it adding fluid makes the noise go away, any time we've pulled a transfer case apart, everything wore out right about the same time so pretty much everything needed to be replaced, including case halves in some cases.
Update.
i drained the 80/90 gear oil and the quart I had added was all that came out so the TC must have been nearly dry. I added two quarts of Mobil 1 all vehicle full synthetic ATF and headed out. As soon as I started moving my heart sank, still making a squealing/grinding noise. berkeley it, i’m going home!
Then, surprise of surprises, as I pulled out of the shopping center the fluid must have worked it’s way into whatever sounded bad. All noises stopped, it felt fine and I cruised on home without a hiccup.
So how do I figure out if it’s hurt? Change fluid once more and send it? Tear it apart anyway? I’d rather not get stranded because of it, but if it’s quiet and pulling fine how bad could it be?
How much metal was in the oil you drained?
In reply to bentwrench :
Surprisingly, none.
Drain in the quarts you put in that made the noise go away. See what they look like through a glass/cofee filter. There's gotta be metal somewhere.....
Must be auto-trak fluid. Those transfer cases have a nasty habit of eating the case because gm didn’t put a similar metal plate in.
See: Patrick, parts for sale, GM transfer case
It may be the pump rub issue that Ranger50 stated. More info here: Pump rub
Yea, it sucks that those transfer cases require the special ATF.
I've had 3 of these trucks now. First "mod" I always do is to get a pump rub kit installed. $300-ish including labour. Saves much grief later on.
You'll need to log in to post.
