Fluid type in 1985 gmc sierra k2500 4x4 aluminum transfer case

check fuses and relays--- fluid levels ---transfer case --actuator movement

Check fluid in transfer case

You can use Dexron 3 or go to a dealer and get the fluid.

If you talk to Royal Purple they will tell you that their synchromax oil is perfectly fine to replace the auto Trak 2 fluid I have used it for years never had a problem in fact I think it's a better fluid than the factory fluid

that atf stand for automatic transmission fluid also in the transfer case you need 80w90

there are two plugs on a transfer case one on the bottom to empty it and there is 1 on the top side for filling it , you will need a manual pump and the proper fluid ,pump in fluid slowly as to not over fill and watch for the fluid to start coming from the fill hole. this is how you tell when the fluid level is correct

First I would check your fluid level. There are 2 plugs located on the rear of the transfer case. Remove the top one and verify fluid level. To repair the leak the transfer case will need to be removed and reinstalled with a new gasket.

Verify fluid level first, add if needed and verify that sound goes away. If sound fails to go away you will need to have the transfer case replaced or rebuilt. I think the fluid is Dextron III ATF. Double check with another source before adding fluid.

Try Replacing the Transfer Case.

check fluid level, check the transfer case linkage on driver side of transfer case for damage /wear or in need of adjustment

The Z71 typically comes with the auto 4wd transfer case (cannot remember the GM number). This requires AutoTrak II, which is available at a GM dealer. Do not use any other fluid in this transfer case! The previous post was correct in the location of the two plugs, but not on the fluid (the other types of transfer cases by GM use ATF). The transfer case is located under the truck right under the cab. There is a small skid plate under it, and a large driveshaft leaves the rear end of the case heading to the rear differential (axle). If you have the manual or electronic w/o auto 4WD transfer case, you can use Dexron III, but Dexron VI is a better fluid that is also now available at your local auto parts store. Again, if you have the AUTO 4WD button in the dash, use the AutoTrak II fluid from the dealer.