[Deskjocky3519]

4wd engages, H and L, no neutral, front axle engages, shift motor new, switch seems to be good (maybe) but keeps blinking, "service 4wd" indicator comes on, shifts erratic in 4L.
What am I missing? Any thoughts?
Thanks

 

[BoiseRob]

What year truck?

 

[Deskjocky3519]

What year truck?

07 LBZ

 

[BoiseRob]

Search results for query: Pump Rub

www.duramaxforum.com

The GMT800 platform suffered from a transfer case Pump Rub issue that would wear a hole in the magnesium transfer case and allow the fluid to leak out.

 

[BoiseRob]

Transfer Case Pump Upgrade Kit | 1998-2007

Looking for Merchant Auto Transfer Case Pump Upgrade Kit | 1998-2007 #10001?

www.merchant-automotive.com

Transfer Case Upgrade Kit (Pump Rub Fix) | DMAX Store

dmaxstore.com

 

[BoiseRob]

It could also be the Front Axle Acuator

Front Axle Actuator

Looking for Merchant Auto Front Axle Actuator #26060073?

www.merchant-automotive.com

 

[BoiseRob]

How's the fluid level in the T-case?

 

[Deskjocky3519]

TC is full and the actuator seems to be working....

 

[BoiseRob]

Then it could be the wiring harness...

 

[groove]

Dash switch may be toast. Recently had same issue and eventually would not shift from / to 4WD. Replaced switch and all is well again.

 

[Deskjocky3519]

Thank you for the help

 

[DuramaxNWA]

If it's not pump rub or actuator it's probably the dash switch. Pretty common for them to go out. Easy peezy to replace

 

[Bsimster]

Had to replace the switch on my 03. Same symptoms, everything else checked ok

 

[zika]

maybe the fluid L. in the T-case? ?

 

[MIkey52]

Could be switch in dash. Easy to trouble shoot as each switch position has a distinct resistance value. My problem ended up being the encoder in the transfer case. Also easy to trouble shoot with a power probe.

 

[AndyKramer]

Check the v ground wire. My 2015 did the same thing. I removed the ground wire on the frame, cleaned up the connection. Worked perfect.

 

[darmah59_6329]

Then it could be the wiring harness...

I have had issues with bad grounds between the engine, transmission and body causing all sorts of issues. There are a couple of common grounds one I think just below the drivers door on the frame. You could check voltages and resistances on the circuit or just try and clean the grounds and see what happens.

 

[Prostreet]

Thank you for the help

Rite under the driver's door , down on the frame , there are several ground wire to frame
connections check or clean (wire brush or sand ) connection area to achieve good grounds

 

[Bsimster]

I have had issues with bad grounds between the engine, transmission and body causing all sorts of issues. There are a couple of common grounds one I think just below the drivers door on the frame. You could check voltages and resistances on the circuit or just try and clean the grounds and see what happens.

What truck do you have?

 

[darmah59_6329]

What truck do you have?

05. I had the exact same symptom a while back and traced it to bad grounds. They looked ok, but were corroded and needed cleaning. As these are separate frame vehicles you need low resistance reliable grounds between the body and frame for things to work properly. I have also had issues with the connections to the transfer case motor as well for the same basic reason.