4wd Whine

TAV8WS6 · December 22, 2009

Hi im new here. I have a 2005 Suburban Z71 and a couple months ago it delveloped a whine when i activate any type of 4wd. In auto4 it whines for about 3 seconds then goes away for a while. When the trucks in 4high it will whine the entire time getting louder with speed. When in auto4 and the rear tires slip, the front wheels dont engage as quickly as they used to.

I believe it may be the transfer case, but im obviously open to anything. Ive already taken the transfer case out, but before i take it apart to see inside I want to make sure it cant be anything else.

When I took the transfer case out it had fluid in the area that bolts to the transmission, shouldnt that area be dry? I think something is leaking there from out of the transfer case.

Also, will working in the tranfer case require any special tools for putting it together? Or will the usual stuff work? What kind of mess am I getting myself into trying to do this myself to save a grand?

Your help is much appreciated, thank you

alwcurlz · December 23, 2009

Hi im new here. I have a 2005 Suburban Z71 and a couple months ago it delveloped a whine when i activate any type of 4wd. In auto4 it whines for about 3 seconds then goes away for a while. When the trucks in 4high it will whine the entire time getting louder with speed. When in auto4 and the rear tires slip, the front wheels dont engage as quickly as they used to.

I believe it may be the transfer case, but im obviously open to anything. Ive already taken the transfer case out, but before i take it apart to see inside I want to make sure it cant be anything else.

When I took the transfer case out it had fluid in the area that bolts to the transmission, shouldnt that area be dry? I think something is leaking there from out of the transfer case.

Also, will working in the tranfer case require any special tools for putting it together? Or will the usual stuff work? What kind of mess am I getting myself into trying to do this myself to save a grand?

Your help is much appreciated, thank you

Sounds like the clutch packs are worn in your transfer case. The clutch pack engages full time when 4WD is chosen, and when in Auto 4 WD only when traction is lost. It shouldn't cost much more than $500 to replace the clutch packs. If the repair shop uses GM clutch pads it'll cost several hundred $ more unless they use Dodge clutch pads. That's what my brother had done in his case. If you're finding oil between the transfer case and the motor, it's likely your rear main seal leaking on the motor which is a very very common issue with these trucks. Good idea to replace it when you have the transfer case off. I've not worked on a transfer case so have no help there as to what tools are needed.