Black/burnt Transfer Case Fluid 2004 Silverado 74k Auto 4wd

bhazely · July 12, 2011

I have a 2004 z71 Silverado 74k, with auto 4wd, my front axles will not engage when in any type of 4wd and all my pushbutton fuctions seem to operate correctly. I just purchased this vehicle 2 weeks ago and am unsure of the history. I thankfully had Matt help me troubleshoot it and he said that my clutch packs may be gone in my transfer case and recommended me checking the color of the fluid. I drained a few ounces of the fluid and found it to be black and of course smelling burnt, good call Matt. I am just wondering if we have any suggestions on how this could have occured with such a low mileage and what you suggest the next step would be on solving this problem. Hopefully my pictures show up, none of the particles in the picture were ferromagnetic so they don't respond to a magnet.

Matt_ · July 12, 2011

Oh man.... sorry to see that.

Next step would be to get some quotes for a tcase rebuild. Or even see if you can order a remanufactured one and swap it yourself (might be cheaper).

Previous owner could have left it in 4wd for a loooong time which would eat away at those clutches. Another thing that I believe would cause this is if someone leaves the truck in auto-4x4 100% of the time. There's a misconception out there that auto-4x4 is 2wd and the only engages when the wheels spin. That's not the case really.... when you put the vehicle in auto, the shift motor adds some preload to the clutches. Normally its not enough to be felt by the driver (but sometimes it is... it was definitely noticeable in my 2005). So if someone leaves the truck in auto-4x4 for 50,000 miles on dry paved roads, I could see that being an issue.

brainpause · July 12, 2011

Oh man.... sorry to see that.

Next step would be to get some quotes for a tcase rebuild. Or even see if you can order a remanufactured one and swap it yourself (might be cheaper).

Previous owner could have left it in 4wd for a loooong time which would eat away at those clutches. Another thing that I believe would cause this is if someone leaves the truck in auto-4x4 100% of the time. There's a misconception out there that auto-4x4 is 2wd and the only engages when the wheels spin. That's not the case really.... when you put the vehicle in auto, the shift motor adds some preload to the clutches. Normally its not enough to be felt by the driver (but sometimes it is... it was definitely noticeable in my 2005). So if someone leaves the truck in auto-4x4 for 50,000 miles on dry paved roads, I could see that being an issue.

I can HEAR it as much as FEEL it in Auto-4x4. And there's nothing wrong with my t-case.

Larry

bhazely · July 12, 2011

Oh man.... sorry to see that.

Next step would be to get some quotes for a tcase rebuild. Or even see if you can order a remanufactured one and swap it yourself (might be cheaper).

Previous owner could have left it in 4wd for a loooong time which would eat away at those clutches. Another thing that I believe would cause this is if someone leaves the truck in auto-4x4 100% of the time. There's a misconception out there that auto-4x4 is 2wd and the only engages when the wheels spin. That's not the case really.... when you put the vehicle in auto, the shift motor adds some preload to the clutches. Normally its not enough to be felt by the driver (but sometimes it is... it was definitely noticeable in my 2005). So if someone leaves the truck in auto-4x4 for 50,000 miles on dry paved roads, I could see that being an issue.

I can HEAR it as much as FEEL it in Auto-4x4. And there's nothing wrong with my t-case.

Thanks guys for you help, I am going with the auto 4wd theory, especially living here in Michigan. Expensive lesson learned on checking all of your fluids before purchasing a vehicle.

Larry