4wd not working

sunnyboy · January 14, 2006

Please help. The truck is a 2000 2500 sierra 4x4 6.0 with 270,000kms. The 4wd, AWD, and 4lo no longer work. The push button selector works fine. I had the truck up on jacks. Pulled the acutator out. It worked fine moving in and out as the different settings were pressed. The fluid was changed. It was very dirty, with thick crud on magnetic drain. On the jacks, the truck would spin the 4 tires in 4wd. When place on the ground the front tires do not work under load. I took the truck to my local dealer and he confirmed that the problem is in the transfer case.

So where should I go from here? Is there something that is routinely relpaced/fixed ? Are there clutch plates in there? How hard is it to do? Will I need to get a different tranfer case all together? Any info would be greatly appreciated. Thanks for your help!

DigitalMike · May 21, 2007

Bump.

I have this same problem on a 2002 Silverado 2500 (non-HD) 4x4. Can anyone chime in here?

millhouse49 · May 23, 2007

there is a clutch pack in the trnsfer case's with auto 4wd. so if you say the encoder motor is turning then 9/10 it's the clutch pack that has failed.

DigitalMike · May 23, 2007

Thanks for the reply. What would be involved in replacing the Clutch Pack?

millhouse49 · May 24, 2007

withstupidremove crossmeber that supports trasmition,then removing transfer case and full disassemble. it's a bigger job especially with out a hoist.

millhouse49 · May 24, 2007

oops that was supposted to say remove the crossbar that supports the trans

Ranger · May 26, 2007

I don't think he has autotrac though...I was under the impression that was in half-ton 1500s...His is a 2500LD right?

millhouse49 · May 26, 2007

auto trac and auto 4wd 2 different things

millhouse49 · May 26, 2007

ether way there is something busted inside of the transfer case and needs to come apart to be repaired!

DigitalMike · May 26, 2007

My 2500LD has the four buttons that say, from top to bottom, Auto 4WD, 2 HI, 4 HI, 4 LO. Also, I did put the truck up on jack stands and with 4 HI enabled, the front wheels spin but I could stop them from spinning just by grabbing the wheels.

Another interesting thing is I too was plagued by the driveline clunk noise which required the slip yoke to be lubricated once a year under warranty. However, once the warranty was up, I found out that all I needed to do is replace the Dextron III (Red) with the AutoTrac II (Blue) and the problem was solved, permanently; no more clunk. FYI, I made this fluid change after the 4WD slippage symptoms started that we are discussing here.

So, back to the Transfer Case; you are saying that I will need to remove the Transfer Case, open it up, replace the Clutch Pak and this will solve my slippage problem? What would have caused this to happen in the first place? Was it the Red fluid vs. the Blue? What can I do to prevent this from happening again? What kind of cost am I looking at in terms of parts if I do this myself?

Thanks again.