so last night i got a call from a kid with a stuck brand new chevy so i went to pull him out and it was in prob 6in of marsh/mud, i was in 4lo hooked them up pulled and hear a big CRACK then i look down and only my rear tires were spinning. so i try to go into 4hi and the same exact thing happened. other people around there said it sounded like the hubs werent locking up right and the crack with them disengaging. another person said it might the be vac tub that pressurizes the hubs may have come undone (havent looked yet) he also said that the same thing has happend to his more then once. it rides perfect in 2wd but it will make this hissing sound every so often, kinda like there is a tube lose and air is getting out of somewhere it didnt befoe.

any of this make sense or anyone else have any ideas?

thanks

 

mine did the same thing, but the next day i put it in 4wd and it was fine

 

I had the same problem a few years ago a couple different times. No luck, every time I tested it worked fine, I took the hubs apart and check them they were fine. I used vacuum pumps and gauges and everything came out fine. I even strapped a video camera underneath my truck and recorded the half shaft and it would never happen. So good luck hope you can get it to work for you.