1985 M998 Driveline Issues

[bushw]

Good Afternoon All,

Been having issues with my HMMWV recently, went to take my truck out for a ride and when I get above roughly 5 mph I start to hear slamming coming from the driveline. Issues persist regardless of transfer case gear and vehicle gear. Thinking I might be needing to take apart transfer case, but am unsure if that's the best place for me to start. Anybody have any similar issues or advice before I get started?

Thanks

 

[Mullaney]

Good Afternoon All,

Been having issues with my HMMWV recently, went to take my truck out for a ride and when I get above roughly 5 mph I start to hear slamming coming from the driveline. Issues persist regardless of transfer case gear and vehicle gear. Thinking I might be needing to take apart transfer case, but am unsure if that's the best place for me to start. Anybody have any similar issues or advice before I get started?

Thanks

.
Might be worth jacking up the rear tires (or the fronts) and turn the wheels. Is the drive shaft wiggling up and down? What about laying down on the ground - and push up on the drive shafts. Do they move?

New truck? New to you truck? Picked up at a Yard... With a forklift?

.

 

[bushw]

.
Might be worth jacking up the rear tires (or the fronts) and turn the wheels. Is the drive shaft wiggling up and down? What about laying down on the ground - and push up on the drive shafts. Do they move?

New truck? New to you truck? Picked up at a Yard... With a forklift?

.

Had the truck for a few years. Had it locked in Low when stuck in the mud. Drove it home with no noticeable issues and parked. Few weeks later, something was binding up and I thought it was the brakes being caked up or corroded due to the moisture, gave it a bit more throttle then it started to move and developed the noise I mentioned before.

 

[Mogman]

You have likely broken something like a half shaft or drive shaft due to the fact you have the transfer case in HL or LOW and have gotten the drive line in a tremendous bind.
Crawl under the truck after making sure it is secure and look at all the drive shafts and half shafts closely.

 

[TOBASH]

Never drive in HL. Only H.

Fixed my buddy’s problem. (He just didn’t understand transfer cases until it was explained).