2004 GMC Sierra 1500 Crew Cab 5.3L 4X4 Z71 93,000 miles

Last night I was driving home and heard a thump then felt my truck bounce in the rear end. Next my tac shot to 6000 so I hit the brake to turn off the cruise control and figured I had busted my rear end. When I stopped I checked and everything looked fine. So I easily started back down the road and 3 miles further it happened again. I stopped the truck and realized I did not have forward or reverse. I used 4 wheel drive to make it to a house to call for help. (Left cell phone at home) I had the lady there put the truck into reverse while I laid under the transmission and it was a terrible sound trying to go in and even worse going back to park. We towed it home and noticied the fluid was 1 quart low. So I added a quart and tried it out again. It ran fine last night. I probable put 5-7 miles on it and never had anymore trouble. Could the low fluid level cause that much of a problem then just go away?

My four wheel drive light has come on and off for six months but has worked fine. My 99 chevy did the same thing before I traded it for the GMC.

I dont know about the tranny, but the 4x4 light is a bad solder connection on the board at the switch, I had the same problem('01 Z-71), wife was driving 70 over the seven mile bridge while I rested, I looked over, and it said it was in 4 wheel drive, I freaked, had her slow down,. and pull over after the bridge, so I could confirm it wasnt really in 4 wheel. I resoldered the board, and havent had a problem with it since(4 years).

Transfer case problem.

Sam

Thanks. Whats that gonna run me $$????

Same thing happened to one of mine. Snap ring came off in the transfer case. Best bet- find one in a yard- it's an easy swap.

www.car-part.com

Depends upon your transfer case. Should not be more than 1k.


Sam

GM has had problems with encoder sensors in the transfer case. This sensor tells the 4wd module what range the transfer case is phisically in. If it is giving a false position indication, it may try to shift it, thus shifting it into neutral. Sounds like what is going on. If there is no other damage in the transfer case, I would say replace the encoder sensor. If you need the GM bulletin or some repair instructions, PM me. I will send you the GM info.

Thanks for help guys. I drove it 11 miles last night to my friends shop. I was 300 yards away at a stop light waiting for it to change. When I tried to go, she never moved. Had to use 4 wheel drive to get to his shop. A$$ behind me would not stop blowing the horn so i flipped him off. Turned out to be my brother screwing with me.

Thats why I HATE push button 4wd. I will choose a lever on the floor any time over a button.....but its just the way the trim levels are now offered by manufactures.