2005 GMC Sierra locked in 4WD Low

[CCR777]

Hi guys - I just joined with hopes someone can lend a hand. Woke up to a truck showing 4WD Low that was just fine (in 2 High) when shutting off the night before. Replaced the dash selector switch and checked fuse with no change. Pulled the transfer case actuator and, when doing so, felt and heard a noise that I believe came for the transfer case. I soon discovered I had no "DRIVE" in any gear. My best guess is the noise indicated the return to neutral after being so bound up in 4WD Low.

 

With the truck shift lever set in neutral and the rear wheels off the ground, I tried to manually move the transfer case spline shaft back to 2HI. I used a pair of channel locks to move the shaft in a counterclockwise direction. At this point, the "key" location for the transfer case spline was facing 6 o'clock with the actuator spline around 12 o'clock. There only marginal movement of the shaft. However, when moving

the shift lever in the cab through the gears, the transfer case engaged and it had returned to 4WD Low.

 

With this result, I surmised that the 6 o'clock position correlates to 4WD Low. And, because the dash shift selection moved from the 4WD Low position to 2HI when the actuator was removed from the transfer case, it seemed plausible that 12 o'clock on the actuator spline was 2HI.

 

I have tried several times to manually move the transfer case spline shaft from 6 to 12 o'clock. The alignment would then be correct and I could reinstall the actuator. However, while the shaft moves within a small arch, it meets resistance ( I am told this mechanism is spring loaded) and basically remains in 4WD low. Any ideas?

 

Update: after an initial return to the 2HI light on the dash selector switch, the switch is now vacant of a selector light. It lights up when starting but the go dark.

[Chubbs878]

There are timing marks to align the gears to neutral above the encoder ring within the encoder motor casing. Then, if you are unable to electronically shift the TC to "neutral" the rear wheels are lifted, auto trans' shifted to neutral, & the TC encoder motor input shaft manually rotated to "neutral" position which aligns with the encoder sensor ring setup.

 

http://www.gm-trucks.com/forums/topic/203153-transfer-case-np246-encoder/?do=findComment&comment=2027941