4x4 problems while turning in dirt

[Cassandra D]

Ok now i have a brain teaser for you GM people out there. I have a 2011 Chevy Silverado 1500 LT 4x4 with the 5.3. I have the electronic shifter panel that has the "AUTO" option for 4x4. When i was on my way to Georgia the lights on my 4x4 switch all of a sudden went out and the dash flashed the service 4x4 soon code. (my truck has 183,000) on it. 

So I didn't use it at all. got home to Texas and changed the four wheel drive actuator drained the axle fluid and now the 2 wheel light will not come back on. The truck is engaging and disengaging. I can hear the Transfer case locking and everything shifting in and out fine. BUT the only thing i am now noticing is that when i test my 4x4 in a grassy or sandy area to see if everything is ok. It turns kinda hard. It was worse until i changed my Transfer case fluid but has not gone away and the 2 wheel light is still off. But it dosen't humm when im going straight ahead and it dosent get stuck going in or out of 4x4. I have no idea what the cause is. 

-HELP!! 

[davester]

maybe read codes for the 4wd system?

[intheburbs]

Not sure what you're asking.  Your truck doesn't have a center differential, so when you're engaged in 4wd it's going to resist tight turns, even on grass or sand.  That's normal behavior.

 

With regards to the 2wd light on the switch, perhaps there's a problem with the switch itself?