Transfer Case Fluid

[Gapper_ca]

I have a 2005. when i changed to fluid it was black as well. then changed it on a short interval and it was very dark. later on i had to replace the entire transfer case. the bushing had come loose and was spinning around inside , full of metal fillings and such. if it is very dark i would check it out. cost me over $2000 to get it rebuilt, should have just bought a rebuilt one, but did not reliaze all that was poched on it.

[CoyleJR]

I am about to change my transfer case fluid for the 5th time in 180k miles. I have always used the GM owners manual recommended fluid GM p/n 12378508. The new/fresh fluid is a blue/green color and a dark dirty motor looking fluid after use. It appears that some DP members are draining the original blue/green fluid that looks like dirty motor after use and replacing it with ATF. Has GM made the determination that ATF is better than the owners manual recommended GM p/n 12378508? I have never had any problems with my transfer case and only want to use the best fluids in my truck. What is the VERY BEST fluid to use in my TC??????????
Thanks
John

[DmaxMaverick]

I am about to change my transfer case fluid for the 5th time in 180k miles. I have always used the GM owners manual recommended fluid GM p/n 12378508. The new/fresh fluid is a blue/green color and a dark dirty motor looking fluid after use. It appears that some DP members are draining the original blue/green fluid that looks like dirty motor after use and replacing it with ATF. Has GM made the determination that ATF is better than the owners manual recommended GM p/n 12378508? I have never had any problems with my transfer case and only want to use the best fluids in my truck. What is the VERY BEST fluid to use in my TC??????????
Thanks
John

The part number you posted is the WRONG fluid. That's Autotrac II fluid. It is ONLY for electronic/auto 4x4, which is NOT available on a 2500HD or 3500 GM truck. That fluid is designed and recommended for only 2500 (non HD) and lesser vehicles with auto 4x4. Your 4x4 system is electric, NOT electronic. Your transfer case should be serviced with ATF, the same fluid you should be using in the transmission. I recommend synthetic for both, especially if towing, and absolutely if towing heavy or frequently. The owner's manual covers several vehicle models, and they are not all the same.

[CoyleJR]

DuramaxMaverick,

I will replace the current fluid with Dexron VI full synthetic.

Thanks
John