Transfer case question GMC....

[specialk]

2005 1500 Sierra push button 4wd auto tranny......my question-does the transfer case and transmission share the same fluid or are they separate units that the fluid levels must be checked separately?......thanks in advance!!

 

[GoldDot40]

Separate. The autotrac transfer cases take a special fluid with friction modifiers in it since they have clutches inside them (engages the auto 4wd). It runs around $9/qt at the dealership.

The transmission takes Dexron ATF. They are divided by a seal inside the output shaft of the transmission. If that seal leaks, then the fluids will mix and one or both of the components will become overfilled. The transmission has a traditional dipstick under the hood by the firewall. The transfer case has a check/fill plug that has to be checked from underneath the truck.

 

[transfixer]

Seperate fluid as GoldDot says, although the type of fluid in the transfer case isn't that critical, you can use ATF in the transfer case and it will work just fine, on my last truck with a 246 transfer case I ran Mobil One 5w20 in it over 4yrs till I sold the truck, no issues and it worked just like it was supposed to.

The Autotrac fluid has a tendency to evaporate over time it seems, disappearing out the vent is the theory, cause those transfer cases are always turning, constantly churning the fluid even when in 2wd,