Transfer case fluid question

MountaineerTom · September 9, 2002

Just a question about the fluid that was used in the auto trac T-cases before GM went to the new "blue" stuff. Was the original fluid red like transmission fluid, or some other color?

99silveradoz71 · September 9, 2002

Tom, when I went down to see Rob(2000z71 on Pacific) last month we did the t-case fluid on my 99. Mine was red in color when draining the factory fluid. I know Rob did his 2000 a week or so later and his fluid was a greenish if I remember him telling me. So on your '99, I'd guess red like mine for the factory fluid initially.

MountaineerTom · September 9, 2002

Bill, your truck has the auto trac and not the manual engage t-case?

HillHound · September 9, 2002

Tom,

I changed my 2001 and it had the blue Auto-trak fluid in it from the factory. I replaced it with the same blue oil from the GM dealership. It's fairly cheap-I think it was around $4 per quart. The filler hole is at the top of the case against the bottom of the body, so you'll need a siphon to refill it after draining the old fluid out.

MountaineerTom · September 9, 2002

Mines red, but it's never been changed. Not having any problems or anything, just curious after checking all my fluid levels today. I always hear about the blue stuff, and that got me to wondering what the old stuff was. I have a pump already, just need to get the fluid whenever I change it.

Thanks. :thumb:

GreenRado · September 9, 2002

Tom,

I had mine changed under a TSB some years ago to stop a really bad case of "clunking", and it helped for about 2 1/2 yrs. The original was red, and the new is a teal color - and I changed it about 2 mos ago - there must be some extra additives for lubrication, buffers, etc because within 10 miles after replacing the fluid, the "clunk" went away.

Don't have the link handy, but I had (in my usual form) a lengthy write-up here. My only advice is to replace both drain and filler plugs, if they're mangled even slightly (previous tech put mine in way too hard), and if you do reuse, GM recommends doping the threads.

Dihappy · September 9, 2002

Ill be doing this soon as it dries up

What is it called?

Can i just ask for Transfer Case fluid at the dealer and theyll give me the right one?

Is it fairly obvious where to drain and fill it from?

How about the tranny stuff guys, what fluid should i use and is it also easy?

Peace!

GreenRado · September 9, 2002

Ill be doing this soon as it dries up

What is it called?

Can i just ask for Transfer Case fluid at the dealer and theyll give me the right one?

Is it fairly obvious where to drain and fill it from?

How about the tranny stuff guys, what fluid should i use and is it also easy?

Peace!

Di,

I'm assuming that you have the Autotrac x-fer case. The current p/n for the fluid is 12378508; you'll need 2 qts. Note that this is a different p/n than what is listed in your owners' manual.

My total, w/ tax was $18.08 for 2 qts. It's pretty straight forward, but be very careful about getting the magnesium drain and filler plugs out (18 mm socket, I think). I replaced my drain plug w/ a new one. GM suggests you dope the old ones if you can re-use them. I used one of those pumps w/ a screw top to fit the bottle, and it's worth it, otherwise it's pretty messy!

For the auto tranny, personally, I'd take it to a dealer, or reliable tranny service shop and have them flush everything, including the convertor, and refill - more expensive, but cheap insurance as I see it!

BTW, Di what make and model are your wheels?

MountaineerTom · September 10, 2002

Henry,

GreenRado is right on with the P/N for the new Auto Trak fluid. I bought 3 quarts today, for $19.something.

If you have a manual shift transfer case, I think it calls for Dextron Tranny fluid, but check you owners manual, it will tell in there.

I have the Auto Trak t-case, and here's my drain and fill plugs. I'm sure the manual shift would be close to the same, if not exactly the same. Obviouly the fill plug should be higher than the drain plug.

MountaineerTom · September 10, 2002

GM suggests you dope the old ones if you can re-use them.

Will teflon tape work? That's what looks like is on mine already, or is it something you squirt/brush on like thread lock? I've seen pipe dope for water pipes, etc, but not sure if this is the same kind of stuff.

99silveradoz71 · September 10, 2002

Tom, yes I have the Autotrac. Can't recall if Rob and I put anything on the plugs or not. I know we brought some lubricant or another out at some point. It may have been the t-case.

Redapple · September 10, 2002

For lubrication of the threads on the plugs, you can try anti-sieze compound. You can find it at any parts store. It is a liquid, and silver in color. Works good. It keeps the threads on alum & magneseum from binding up on each other.

Bill

GreenRado · September 10, 2002

GM suggests you dope the old ones if you can re-use them.

Will teflon tape work? That's what looks like is on mine already, or is it something you squirt/brush on like thread lock? I've seen pipe dope for water pipes, etc, but not sure if this is the same kind of stuff.

Tom,

I guess it's already been answered by Redapple now, but that sounds good to me - I only know it needs to be OK for aluminum and magnesium. The stuff on the new plugs was white-yellow in color and was not soft or watery.

I used teflon tape, but in retrospect I'd not advise anyone using it - got to thinking "what ifs" about some of it getting into the case and contaminating. From a chemical standpoint, teflon if very inert (wife is a chemist), but I would wonder about the mechanical clogging, but there is really very little that would get into the case anyways.

No ill effects or leaking yet, and it's been ~ 3500 miles.

MountaineerTom · September 10, 2002

Thanks all.

GreenRado, does the stuff come on the bolts already? It kind of sounded like it did in your last reply. I may just get new plugs. They can't be that much.

BTW, I'm going to do mine like the TSB suggests by draining the old red fluid out, refilling with new stuff, dive a minimum of 5 miles, then drain and refill again. After the second drain, I'll just put some new plugs in. I guess that just helps to flush out all the old red fluid.

GreenRado · September 10, 2002

Tom,

You got it - the plugs come already doped. They use an 18 mm socket, and since the dealer put them on VERY tight when I had the TSB work done, I slipped off once or twice, and while they were still usable, it just seemed better to replace all - that mag is pretty soft!! I think they were about $7 ea, and the dealer parts only had one.

I'd agree the flush routine seems like a good idea since you have the original red stuff in there.

Keep us posted!

Daryl