Slipping or Clunking in 4 wheel drive

[consultIII]

Originally Posted by jnsbanman

All the info I could find says for the manual transfer case to use dextron III. I check the bill and that is what Mr Lube put in (atf).

Maybe it was just to far along to recover... Well the hunt for a transfer case begins.

yikes cold in winnipeg

for next t-case fluid change:
type of fluid depends on which t-case you have. Your truck can have 3 different tcases which all take different fluid. ie. auto trac (blue colour) is for 4button selectable tcase.

easy way to verify your tcase is checking the build codes (RPO)in your glove box:
manual t-case build code is NP2 takes Manual Transmission Fluid, gm Canadian P/N 88861801

auto t-case four wheel drive, NP1 takes auto trac II

auto t-case all wheel drive, NP2 takes dextron III auto trans fluid which have different friction co-efficients than dextron VI. For this reason don't substitute the later dextron numbers (4&5) which is usually acceptable.

One thing I don't do when shifting on the fly is accelerate until the shift indicator stops blinking and the shift is complete.