2nd Gen Non-Engine/Transmission Drivetrain locked up @ 40 MPH

[SPine]

I was going about 40 in 4H when heard a noise that went from a slight buzz to a loud grind 1/2 second later. Before I had time to even think WTF is going on I was fighting to keep it straight and prevent hitting an oncoming semi. What I think happened is that the rear wheels (on ice) and left front (on pavement) locked up causing the rear end to come around to the right. The only skid mark was from the left front. I still had limited steering so the right front must have freewheeled as there were no skid marks. When I got stopped I was halfway on the road and the first thing I wanted to do was move about 10 feet so I would not get hit from behind, blowing snow had visibility pretty bad. However I could not move forwards or backwards, only load the converter. After a few attempts at rocking back and forth easy I was able to get off the road. After the adrenaline rush wore off I tried shifting the T-case:



4L Locked would not move

4H Locked would not move

2H Worked just fine so I limped 3 miles back home



Tonight I messed with it some more. I now just have a real bad grind in 4H and 4L, 2H sounds fine. I read the NP 241 DHD freewheels the front output in 2H so I am thinking the chain may have jumped? I think my next steps will be to drain the oil and check for metal and or take the front driveline off and check for noise again. I noticed some play (<1/16") in the front axle input, I don't think its the cause of my problems but wont rule it out. I have never had a T-case apart before and really don't know much about how it works or what could be broke. Any suggestions would be appreciated.

 

[SRath]

That's a scary story. Strengthens my resolve to switch to an NP205 cast iron gear drive t-case.

 

[JMcCoy]

X2 on the NP205. I can't remember whether or not the 2001 rams had a vacuum disconnect. My vacuum CAD got water in the it and would only partly engage. It would make a buzz noise then slam in and out of 4WD. The whole truck would jerk and jump. This took place in sugar-sand. The roads don't freeze too often down here in south Florida Good luck