2006 Chevy Silverado V8 Four Wheel Drive Automatic 80000 miles
When engaging the 4 wheel low there are loud poping noises. This noise sounds more like a clanking of objects together. Imagine that you are knocking on a piece metal, this is the sound that occures. The noise is repeditive and occurs about 3 times before the system engagues back into the previous gear selected. If you were in 4WH then you go back into 4WH, and same for 2WH. I have tried to engauge 4WL from 4WH & 2WH both; in neutral, in gear moving slowly, & in reverse. I have not owned a electronic 4 wheel transfer case before and need some advise. I do not believe the switch is bad because you can hear the soleniod operating on all 3 selections of gears & all the lights do work on the dash gauge selection. 4 wheel high works properly and the truck engauges in and out of 2WH AND 4WH fine. What could the problem be? A soleniod, an actuator, Ive heard of an encoder moder?, Or did I get a bad transfer case?
Have you checked to make sure the front u-joints are good? Also, when shifting to 4lo, many times it is common to hear a clunk. You are changing the gears in the transfer case and they can make noise. That can also happen from lo to high.
Let me know about the u-joints. IF they seem good, you may want to have the 4wd actuator on the transfer case checked. It may be hanging up and slow to shift.