GMC Sierra 4WD encoder/shifter motor

[06pirate]

I've been having trouble with the 4WD shifter encoder/motor on my 2006 GMC Sierra X-Cab for some time now. The truck has 128,000 miles on it.

 

I intermittently get a "SERVICE 4WD" message, and when I do get that, the system will not respond. Sometimes it fails to shift even when there is no warning message. NOTE that this only happens when the air temp is below about 45* or so. When it is above 50* it works fine.

 

I replaced the switch assembly on the instrument panel (all the lights were burned out anyway) and that did not fix the problem. This was an OEM unit purchased from the dealer and it was made in China.

 

I will do some more troubleshooting before I replace the existing unit, but if it turns out to be the encoder/shifter assembly then I will replace it rather than fool around trying to repair it.

 

The question I have for the more experienced is what brand of new unit? I can get the OEM unit from the dealer for $440. NAPA has a new Dorman unit for $260. I will not deal with eBay nor Amazon. I have seen Dorman parts mentioned many times but never used their products. I'd be interested in recommendations either way, or any other brands you have found to be OK. I will pay for quality, as I use this truck to go miles back on logging roads, etc., when I go hiking and don't want to get stranded it I ever go to shift the thing and it ends up in transfer neutral or some other fiasco. It has to work.

[kstruckcountry]

You need to scan it to be sure. When mine went out it gave me no warning and never any light. Just shifted to neutral and quit.

 

I would pay more for the better part. I'd also have them add a case saver while it's apart.