just bought the truck a few weeks ago. i like to change all the fluids and filters so i know when they were done last, you never know what the last guy did.

any way i changed the oil (replaced with amsoil Synthetic Heavy-Duty Diesel & Marine Motor Oil ) rear diff (amsoil severe gera 75w-90) ant transfer case( amsoil ATF) the old transfer case fluid looked bad to me. it was not real red it was almost black. should i be worried? the truck as 53000 on it. who ever owned it before me did some serious miles hauling on it. i do not know how much he hauled.

i have also changed the spin on tranny filter and the fuel filter. after winter i will do a full tranny flush and the front diff.

If your truck has a Auto Trac transfer case, then you need to dump the fluid and get the fluid from the dealership. Auto Trac transfer case requires the GM only fluid.

Hope this helps.

no, truck does not have auto track. just 2x4, 4x4, and 4x4low

i guess i should not worry about the trasnfer case fluid being dark? anyone?

If your truck has a Auto Trac transfer case, then you need to dump the fluid and get the fluid from the dealership. Auto Trac transfer case requires the GM only fluid.

Hope this helps.what is auto trac?

It's an automatic 4wd systems available in the 1500 series truck/tahoe/suburbans. It requirers a special (dealer only) AutoTraK fluid. Not stout enough for the 2500HD/3500HD trucks.

DEWFPO