Diagnostics help. Possible failed transfer case?

[tremmert]

Hello,
I have a 1987 M998 w/ 38k miles and the 6.2L. The vehicle has run fine for the past year. Last month while driving, I heard a loud clanging noise from under the vehicle and lost power. Pulled to the side of the road and parked it. When I tried to resume driving, the vehicle went in reverse w/ a loud clanging noise. I stopped, then switched the TCase to HL and the vehicle worked fine. I was able to get it home. When switching back to H, the vehicle wants to go in reverse again with the loud sound.

I am assuming this is a problem with the TCase. If so, does anyone know any specifics on repairing the unit? Or what might be wrong?

Thanks

 

[NDT]

Sounds like the problem is related to the interaxle differential inside the transfer case. Most of the time these 218's are not worth fixing. I would put a want ad up, lots of folks are upgrading to the 242 and have a 218 as a waste product.

 

[Wire Fox]

Hey, what do you know...I have a 218 sitting around. I'll shoot you a PM shortly.

 

[snowtrac nome]

I think I would look underneath check axle shafts and differentials make shure the failure isn't one of those items first a worn slip yoke will also do that

 

[tremmert]

Thanks for the advice! This is new territory to me. Do you have any advice as to how to properly inspect this?

 

[porkysplace]

Thanks for the advice! This is new territory to me. Do you have any advice as to how to properly inspect this?

Probably a got idea to read section 8-1 of this manual

TM-9-2320-280-34.pdf

 

[tremmert]

Thanks for the link... TM is always a good read!

I reviewed sections 8 and 9 for removal/installation procedures, but didn't see much regarding troubleshooting my issue. Tomorrow, Ill get the vehicle parked in the garage and visually look for any damage.

Thanks for yalls help

 

[NDT]

You know I think snotrac may be right, more likely a blown CV joint, the "goes in reverse" is what I have never seen, usually with a blown CV it won't move at all.

 

[tremmert]

I could be completely wrong, but wouldn't a blown CV behave the same way in "H" or "HL"? When in "HL" the vehicle is good, and behaves normally. I am just mentally trying to understand how the vehicle would go in reverse when in "H". Any thoughts?

 

[erasedhammer]

Had the same problem. Don't change the transfer case just yet, it could be a waste of time and money.
For me if was a CV joint in my left rear half shaft. Vehicle will work in HL and L with a half shaft broken, but not Have. With a broken CV joint there will be no visual differences, but start there

 

[Action]

The transmission is what changes the direction (forward, reverse).

 

[tremmert]

Thanks for the info! I finally got the vehicle in the garage, and discovered a broken CV on the rear right (passenger) side. I did pickup the TCase just in case, but I will start with the half shaft. Next problem, is trying to find one locally!