M998 no power in the front wheels and driveshaft locked

[Josh998List]

Ok, so got stuck in the mud in low lock 1993 m998. Herd a small clunk and lost the front wheel drive. Actually it locked the front wheels completely. Rear wheels only drive in lock. Any ideas?

Everything looks good in the front diff. Drive shaft coming to the front does not turn when in gear. Spin the front wheels one turns one way the other turns the other way freely.

 

[Coug]

Ok, so got stuck in the mud in low lock 1993 m998. Herd a small clunk and lost the front wheel drive. Actually it locked the front wheels completely. Rear wheels only drive in lock. Any ideas?

Everything looks good in the front diff. Drive shaft coming to the front does not turn when in gear. Spin the front wheels one turns one way the other turns the other way freely.

I assume you mean it doesn't turn when in gear with the engine running, or just generally won't turn when transmission is in gear but engine is off?

Obviously somewhere something is broken. If everything looks and operates properly in the front diff it could either be the transfer case has an issue, or one of the half shafts is broken, but still has enough resistance that it spins the differential then turned by hand, but lets loose when more power than that is applied.

 

[Josh998List]

The driveshaft from the transfer case to the front diff does not turn regardless of what gear it is in. But the half shafts from the front diff to the front wheel gearboxes spin freely, but opposite each other

 

[Bulldogger]

The driveshaft from the transfer case to the front diff does not turn regardless of what gear it is in. But the half shafts from the front diff to the front wheel gearboxes spin freely, but opposite each other

Spinning opposite each other when turning one tire manually is normal. It sounds like a transfer case problem. Have you tried disconnecting the front propellor (i.e. drive shaft)? If the T-case output yoke doesn't turn when the propellor is disconnected and engine running/in gear, the T-case has a problem.

Bulldogger

 

[Josh998List]

Spinning opposite each other when turning one tire manually is normal. It sounds like a transfer case problem. Have you tried disconnecting the front propellor (i.e. drive shaft)? If the T-case output yoke doesn't turn when the propellor is disconnected and engine running/in gear, the T-case has a problem.

Bulldogger

I will try that

 

[Coug]

one other thing, with all 4 wheels on the ground and shifter in neutral, try rolling the truck forward and watching the shaft.
Then after you remove the shaft roll it forward again and see which of the 2 flanges spins. Whichever one doesn't (either the differential or the transfer case) is the broken part.

 

[Josh998List]

Definite transfer case detonation. So, where is a good place to get one of these?

 

[Wire Fox]

Well, I would've been a great source until about a month ago when I sold my spare. Now, I'd just post up a wanted ad in the classified. Plenty of people have transfer cases, just need to let them know you're in need of one. Failing anything reasonably close/shippable, you can try for rebuilding that if the case isn't damaged.

 

[AOR]

Out of curiosity what model transfer case is that and what were you doing when it failed?

 

[Crapgame]

NP242 are rebuilt all the time, just buy a rebuild kit, the specific parts you broke, or pay a shop to rebuild it, install new seals (that tend to eventually leak anyway) Here at the bottom are a couple rebuild kit options for early and late H1: https://www.drivetrain.com/parts-ca...s/transfer-case-np242-rebuild-kit-and-drawing

Several YouTube University of Mechanics videos available, not like it is a 4L80E transmission that needs rebuilding with all multitiude of seals and valve plates.