Np231 Pops Out Of 4Wd

[702_MJ]

I have an 86' MJ with a 231 transfercase, lately when I put it in 4hi and start to drive itll pop out of gear and Ill hear this horrible grinding sound, like it disengages partially! It still has a little forward motion when this occurs, and when I mess with the gear shift and take it out of 4hi and put it back in it does the same thing, like its not engaging right. I checked the linkage and spun the drive shafts today, the linkage is pretty tight, theres some play in it at the handle and a little side to side down by the pivot but nothing front to back, and when I spun the driveshafts everything was moving correctly, no binding or anything and the front tires were spinning, has the typical play with gear wear I think. I might put it on stands and try see what it does when power is applied. I'm hoping the problem isnt inside the case itself. Anyone have any suggestions, or what to specifically look for in play in the linkage or any of that? Thanks in advance.

[mvusse]

How do you have a 231 in an 86? Did you swap it in?

 

Anyway, sounds like it is just barely engaged when in 4 high. Maybe the linkage needs adjusted.

[Mountain Dude]

Ya, try pulling the lever a little farther past the detent for 4 hi towards but not all the way towards neutral. This will conform that the linkage is mis-rigged.

[coyote kid]

try adjusting the shift linkage or maby its a broken or cracked fork ?

[ftpiercecracker1]

Have you ever removed the CAD?  You may be mistaking the collar not fully engaging and slipping off, for a faulty T-case. Its easy enough to get to and fix, so that would be my very first action.

[64 Cheyenne]

Make sure motor and tranny mounts are in good shape, mine used to pop out in 4low till I

adjusted the linkage and replaced worn mounts.

[cruiser54]

Have you ever removed the CAD?  You may be mistaking the collar not fully engaging and slipping off, for a faulty T-case. Its easy enough to get to and fix, so that would be my very first action.

Great idea..

 

http://comancheclub.com/topic/17377-cad-fix-1/

[skidoo_j]

Get one of these, install it and give us a good review.   http://www.novak-adapt.com/catalog/shifters/sk2xc.htm

[702_MJ]

Mvusse, my dad swapped in a 92' 4.0 AW4 231 and the front axle from donor Cherokee. So the CAD is gone. I'm gonna go try mess with the linkage some more, cuz it still feels like to me it's not engaging all the way. My cousin thinks the front driveshaft gear in the case is worn and the chain is just slipping...I'm hoping not so.

 

Skidoo_j, that is on order, not because of this problem but because my cousin has it on his MJ, nsg 370 swapped in, and he loves it.

[mvusse]

I have had three transfer cases with a slipping chain, all three were due to a stretched chain, never a worn sprocket.

 

Quickest way to stretch a chain is driving the truck (even in 2wd) without hardly any fluid in the transfer case. A few hundred miles of street driving will be enough to do it. Don't ask me how I know. :oops:

[702_MJ]

Mvusse, thinking about it I think that may be the case in this situation....bummer.

[mvusse]

Chain is not difficult to find, I got mine from Morris 4x4. Not terribly difficult to install, either, as just the back part of the case has to be taken apart. Most of it stays assembled. Can even be done with the case still under the truck without too much difficulty.

[702_MJ]

I'm sure, but a pain in the but to ship to Hawaii haha!

 

I have an TnT long arm kit, Ax15 and 231 hanging off its rear end waiting to go in, guess its time to take a few weeks and put it all in. Ill check that other 231 first and maybe put an SYE in and change some seals on the trans.