I recently bought a 2005 silverado with the 5.3. The rear diff was out and it was cheaper to replace the whole rear axle with a used one than to buy a new diff. Also it had 4:10 gears and I didn’t care for that so I found a rear axle and front diff with 3:73’s. After I got all that installed the 4wd is giving me problems. I click the button for 4 Hi and it blinks a few times and then lights up. Normal. On jack stands it looks like it works. But in the snow only the rear wheels spin. Now when I push 4 Lo same thing but there is a clunk but on jack stands the front tires don’t spin. Neither does the front drive shaft so it isn’t a front diff problem. So what I’m wondering is does the t case need rebuilding or is there some easier fix I can’t find. Thanks in advance.

 

what tcase you have? have the tcase module code read and post them here

depending on your build....unplug and remove the encoder motor....move the shaft end on the tcase with a wrench to manually perform the 4wd shift....drive it to see if the front prop shaft moves

 

The t case is an np246. The pickup has no codes.

 

tccm will set chassis codes so a cheap scan tool can't access them...full function scanner required.