NP231 has 2WD low, but no 4WD low

[National Drivetrain]

I swapped a t-case and live front end under the Cherokee 2 years ago for the Baja 500.

I had to swap the planetary to the smaller spline to match the trans I got from a junk yard.

While putting it all back together I noticed it was able to go into 2WD low and 4WD low. (I didnt know they could do that...)

Anyway, everything was hunky dory during the 500 but with the stock Cherokee shifter it would pop out of 4WD every once in a while.

To cure the problem that I thought may be the unabody playing games I ordered a Novac shifter that mounts to the t-case and not the body.

I cant honestly say that 4WD low ever worked again, but I'm not sure. It doesnt get put into low very often.

I've played with the linkage ect.

I took the linkage off and shifted it by hand with the tire off the ground and can not get it into 4 low. But I've got 2 low all day long...

Any clues?
Bent mode fork??
Thanks,
Eric

 

[vetteboy]

I guess the first stupid question is, do you have 4-hi?

By nature of the detents in the 231, the shift mechanism moves the mode fork first (2wd to 4wd) and the range fork second (4hi to 4lo). If your mode fork is severely worn or bent, I could see it not fully engaging the sprocket for the front chain, and the mechanism works such that the mode fork doesn't move between 4hi and 4lo, so you'd see the same result in each.

Quick answer is, 231s are a dime a dozen, stupid simple inside, and rebuildable without hardly any special tools or equipment - if you've got time, pull it and rebuild it, if not, swap a known good one in there. Either way it's an easy weekend job.

 

[cher96]

I run a Novak Shifter, however my NP 231 has the Factory Combination of 2H, 4H, N, 4L.

It must have the aftermarket “2 Low” Shift Plates in it. The Novak Shifter accommodates the 2 Low Shift Position in a NP231.

 

[cher96]

Advance Adapters SYE with 2 Low Shift Fork Install Page.

http://www.dirtroad.com/2-low.htm

Hope this helps.

cher96 Vicki

 

[cher96]

TeraFlex 2WD Low Range Kit For NP231-J Transfercase
http://www.quadratec.com/products/52254_200.htm

Instructions in PDF Format:
http://www.quadratec.com/Assets/Installation/26097.pdf

Hope this will do the Trick.

cher96 Vicki

 

[National Drivetrain]

I guess the first stupid question is, do you have 4-hi?

.

Good question. I forgot to mention that.

Yes, I have 4WD High no problem. That's what stumps me a bit. If it has the 2WD Low plate in it, which is deffinately possible, is it somthing with the plate or a fork?

If I can narrow down the problem child I'll get the parts before I yank it out.
I've got a run this weekend and next, so I dont want it to get stuck in the garage...

Thanks