2009 silverado crew 4x4 stuck in 3rd gear and service 4x4

[Breaves]

While I was on a dirt road in 4x4 I stopped to back up and turn around. During the turn in reverse my truck acted like the tranny slipped out of gear and rpms went up. I shift to park and back into drive. 4x4 was still engaged. Now I have service 4x4 and while on the highway stuck in 3rd gear. Also feels like in 3rd gear from take off

[Breaves]

I have a clunk when going from drive to reverse and back to drive like it's in 4x4. It will spin the back tires while in reverse. It will not spin them over going forward. Its really really weak

[Breaves]

Or maybe it's stuck in 4th gear. It running about 3000 rpms at 50 mph

[Cosmic Charlie]

Try a start with the gear selector in "L" or 1 (not D)

if that works and you can manually shift from 1 to 2 to 3 .... then you have a broken front Sprague in the tranny ...

also if it jumps out of forward or reverse and into neutral by itself (but the shift indicator read still read "D") - it's the front sprague

 

the sprague requires a tranny rebuild - at least the sprague - and other components if you chose

you can drive it manually broken for as long as you like

[Breaves]

It only has p r n d m. No low or 123 selection. No the Manuel mode does not work

[efritz]

Try a start with the gear selector in "L" or 1 (not D)

if that works and you can manually shift from 1 to 2 to 3 .... then you have a broken front Sprague in the tranny ...

also if it jumps out of forward or reverse and into neutral by itself (but the shift indicator read still read "D") - it's the front sprague

 

the sprague requires a tranny rebuild - at least the sprague - and other components if you chose

you can drive it manually broken for as long as you like

This does not have a 4L60E.....

 

The transmission sounds like it is in limp mode, they lock in third when they are in limp... You should have transmission codes a shop with a good scanner can pull, you cannot service the newer series of transmissions without one.