Bradymurakami

My 4wd is not working on my 2002 Silverado. It does not have manual locking hubs but automatic. I checked my switch on my dash and it works. I changed the actuator and it works. When I switch into 4wd it engages and locks in but still no 4wd. Just to check I put it on jack stands and put it into 4wd and my front tires spun. I thought it worked for sure after seeing this. I parked my truck on some ice and put it in 4wd and pinned it quick but my fronts wouldn't spin? I also checked my front differential oil to see if metal would come out and nothing. I checked my transfer case fluid to see if there was metal and nothing. I did notice that my transfer case oil was black so I changed it. I have no clue what it could be?

Allan In NE

Tell him the issue lies inside the transfer case.

Allan

ToooTall1

First of all did you use the proper oil for the TX case. Uses GM Auto-Trak 11 Blue in color. When you are in 4x4 with the front off the ground put tx in 4hi wait for light and tx case to change then try to rotate one tire. Engine off but with ignition on, if it is locked nothing may be wrong with it. If not then take out the front actuator on the front differental and push in with a small socket extension and see if the front axles lock with the drive shaft. If they do then possibly the actuator is bad or no power is getting to it. Any other question send me a message. I have three Silverados and two are electric shift