I've got a 1999 Silverado Z71, 5.3.after the last big snowfall,and numerous days in 4hi .i noticed abit of vibration and more noise coming from front end of the truck . after some investigation i realized the transfer case is still engaged even though the dash selector says its back in 2wd.it will still switch to 4lo .any help would be greatly appreciated, thanks

 

You've tried putting it in nuetral before switching? Were you just driving around in the snow with 4hi or did you actually need the extra torque?

 

yea i tried neutral .it releases the front diff.but the transfer case and front drive shaft are still turning with the transmission.i actually needed the 4wd we had 30 inches of snow and it took road crews almost 4 days to get all cleared.i just didnt realize that the trnsfer case wasnt disengaging as the dash indicator shows 2wd

 

ahh... well, it might've toasted something. Driving around in 4hi a lot can do bad things. I try to stick to 4lo unless I really need the extra torque that 4hi gives.

 

bsball, I think you're getting the two confused. 4hi is what is used most of the time while driving around, 4lo really drops it down and doesn't allow you to drive very quickly.

 

actuator in t-case might have gone bad. do you have a service 4wd system message on the dash?

 

Unplug your battery for awhile and hook it up and try it again. My buddy has a similiar to mine and he hit a mud hole and it did the same thing. We unpluged the battery for awhile and hooked it back up and hasnt acted up since.