I was driving down the highway to day and let off the gas on the top of a hill and the speedometer dropped down to 15 mph and then when I put my foot back on the gas the speedo flew up to 100 mph but it wasn't pulling at all so I pulled over and there was nothing. No forward or reverse gears and it grinds when I put it in park but wouldn't keep the truck from rolling once in. I had it in 4wd when it happened due to snow packed roads. I've been having problems with the shift on the fly engaging if the truck is moving, only engages when stopped. Do you think there was something messed up with the transfer case that finally went or what might be wrong. Any advice would help a lot, I don't have a lot of money to throw at it right now and don't wanna fix something that doesn't have to be fixed. I've heard trannies and tranny swaps cost over 2,000. Please help

 

Sounds like some teeth are damaged inside your transfer case. Gonna have to disasemble it to find out whats worn or damaged. Could check for GEM (if its a 97 or later) codes but there probably wont be any.

 

Do you have the electronic shift on the fly?
The fact that it will not go into 4Hi except when stopped could be either the T-cae or the front axle. becasue it grinds when you put in park and it doesn't hold i suspect the T-case is not shifted properly into gear. Need to know which T-case it is.

Regards

Jean Marc Chartier