I have a 98 Sport with the v6 an auto tranny and the nv231d transfercase the problem is it is completely destroying the transfercase, exploding actually. It acts like the front end is engaged and i have been told that there is an acuator in the front differential that is supposed to unlock the front end that is vacume operated but for the life of me i cant find it. I've researched ALLDATA diy, chiltons ect. and they make no mention of it. Anyone have a clue as to what to look for or what could be going on. The t-case linkage was adjusted right ( i jacked the truck up , ran it to make sure ) so thats not the problem. Im stumped. Thanks

 

I have no idea.. i heard something about that too.. but I know mine; a 97 44RE with HD transfer case does not have nothing like that.. matter of fact most of the 4x4's both in Jeep and Dodge of this era had nothing to do with the actual axel to unlock something. When the truck moves the front dif turns and so does the drive shaft. The part that engages/disengages the chain is inside the transfer case it self. I forget the part name but yeah..

 

There is NO vacuum actuator in the front differential. If the truck is moving the entire front drivetrain is moving. It only disconnects at the transfer case.

Are you in 2 hi?

The 231d is a part-time transfer case. You can't use 4wd on dry pavement.

 

Yes it was in 2wd thats why i cant figure it out. The only thing i've seen that comes close is in the alldata info there is a vacume actuator listed in the decription of parts for the transfer case. I clicked on it and all it said was to replace the t-case. I've been into these t-cases and nothing is vacume actuated. That's why i was posting here. I want to buy a new t-case for the truck cause it has a brand new motor, new computer , freshly undercoated , and a new interior. I've spent alot of time on this terd and dont want to just give up but i'm not gona spend a grand to have the same thing happen.

 

Just for kicks, pull the front driveshaft. If your problems stops, its in the transfer case. If it continues, it is in the front differential or maybe a bad cv joint.

 

You said it exploded, so its hard to tell. I had one where the rear driveshaft had a bad u joint and tweaked it. Cracked the case in the back and the front. Can you post a picture of the damage to the case?
Do you have the truck lifted? that changes the geometry on the driveshaft and can cause problems. Also the front driveshaft, since it runs all the time, could have a bad u joint or planetary gear.

I DO have a 231D transfer case from a scraped 97 V6 4x4 Sport with AT. The one I bought for like $250 when mine went, has around 90K on it now. I'm asking $200 locally, think it may ship UPS if its under 70 lbs.
Also a rebuilt front driveshaft for $75 locally.
Maybe cheap way to go until you work the bugs out, then get the new one later on. Let me know.