99 silverado 1500 4wd (nbs). it has the auto 4wd. ive read that some people run the autotrakk II. the question is do i have to? of can i use ATF like i always have? ive heard of people running both i already have ATF for it that i want to use since i read that people have ran both. does it really matter? 4wd gets used in winter seeing that i live in wisconsin right now.

 

I think you need the special fluid for that one. For the ones without the auto function you can use normal trans fluid.

 

Auto 4x4 you have a silicon viscous clutch to consider. The thinner ATF will burn that t-case up in a heartbeat because the clutch will operate at higher temperatures than ATF is designed for.

The transfer case is not just an oil bath either, it includes its own low pressure pump and lubricating system. Wrong fluid = Failure

 

thanks boys you saved me a T-Case! ran the autotrak

 

I found out the expensive way, you must run the autotrak fluid, I burnt out all my clutches, which by the way leave a very bad smell in your buddy's shop that lasts for days