I need some input on a new issue with my NV271 Manual Transfer case. In the past it has jump out of 4x4 a few times, but each time I just pull the lever back into 4x4 and it goes up the hill no problem. This weekend while towing my tandem axle trailer with my 2 quads on it up the (really) steep hill to hunting camp it jumped out of 4x4 and really wouldn't stay in gear while making a pretty bad sounding thumping noise. My first thought was it sounded like the transfer case chain was skipping teeth on the sprocket but after doing a little online reasearch I am now wondering if it may be a bad detent spring/ball or maybe a worn out manual shift fork and what ever the fork engages. I am a retired marine mechanic and in my business it was common to find worn "dogs" on the sliding clutch. Does the shift fork suffer a similiar common failure. I am trying to locate rebuild parts before I disable the truck and pull the transfer case out.

BTW; I did hold the 4x4 shifter in gear while trying to make it up the hill in the mud.

Sorry for the long post but any ideas pointing me in the right direction would be greatly appreciated.

 

Mine was doing the same thing about 4-5 months ago. Mine had a leak and ran dry on fluid before I got it into the shop. Better check the fluid level ASAP! I ended up having to replace my whole t-case.