4wd lo stuck

[RalphC21420]

I have a 2005 Tahoe Z71 that I was topping off the diffs, so I engaged 4hi and struggled to get back to 2hi, long story short I did the same on 4lo but now it doesn’t engage 4hi or 2hi I hear the gear change but it stays in 4lo. Tried putting transfer in neutral but it says service 4wd on dash then goes away. Any suggestions on what is going on. TIA

 

[rockola1971]

I have a 2005 Tahoe Z71 that I was topping off the diffs, so I engaged 4hi and struggled to get back to 2hi, long story short I did the same on 4lo but now it doesn’t engage 4hi or 2hi I hear the gear change but it stays in 4lo. Tried putting transfer in neutral but it says service 4wd on dash then goes away. Any suggestions on what is going on. TIA

If you never put Tcase in Neutral successfully, you arent in 4lo. Your indicator light may say you are but you are not. This is a common failure. The position indicator built into the shift motor for the Tcase is dirty and the system doesnt know what position the Tcase is in. Sometimes shutting vehicle off for a couple minutes and then pushing 2wd will cause it to get back to known position but youll be fighting this problem until your replace the shift motor or atleast just its position sensor (commutator) and it is a separate part that can be purchased. Meanwhile you can pull the shift motor off and manually put Tcase in 2wd. Leave shift motor off until it is repaired.