Hello All. New member and first time poster here. First I wanted to say that I love the site! Although I just signed up, I've used this site many time for help & info and y'all my #1 butt de-pickler.

My question:
I've got a 1988 Cherokee, 4.0L v6, 4x4, Auto & NP231 Transaxle that is having Transmission problems. I'll give you more details and history below but the short of it is that when I move the shifter out of park to any other gear from R to 1-2 nothing happens. Transmission will not engage and idle stays constant. There is no grinding and everything sounds and feels just like it did while in Park. .

I have no experience with Transmissions so I wanted to post my problem first and get some guidance from y'all on where to start. My HOPE is the instructions I get back don't say something like... "Pull out old Transmission, open a beer, put in new Transmission, open another beer, Now make small weeping sound while looking at empty bank account". Help me Cherokeeforum.com!!! Your my only Hope..

So far I've only checked the Tranny fluid and its reading at 3 1/2 inches above the FULL mark. This reading is from a cold Tranny since I can't drive it around and I have no clue if this is good or bad. I would think bad... Fluid looks clean, color is good (lite red) and smells just like it suppose to. No CEL light but the 2H light stays on. Not sure if its suppose to stay on all the time or not but any warning lights on my dash are suspect after all the wiring problems I've had.

History:
I bought this Jeep off of Craig's List back in December. It had been sitting unused for over 2 years but it came with a newly rebuilt engine but it wasn't installed and sitting in the back of the Jeep. I know that's risky but the body & interior looked almost showroom new, new wheels, 4" lift with heavy duty lower arms, good quality shocks, plus the price was right so after spending some time talking to the owner, I felt the risk to me was minimal. But I was so focused on the motor and making sure I had every nut & bolt that I never asked him about the condition of the Tranny. I've never done anything beyond brakes and routine maintenance before so I took my time to educate myself and to test, clean and paint every nut, bolt, and doodad before installing it. It took me about 2 months to get her all back together and another 3 months in Diagnostic Hell trying to figure out why it wouldn't start. The fuel tank was full of old gas and packed with corrosion that had eaten everything rubber in its sights. Fuel lines all the way to the fuel rail were clogged up. All but one injector were toast. I spent 2 weeks just fixing or replacing broke and damaged wires. And of corse completing most of stuff on Cruiser54's Renix page. One of those shorted wires had also cooked the ECM so that had to be replaced. 3 months of this without success is mind numbing!!! I had fixed everything and every test I did passed dead on right. It would crank but never spit, sputter, or fire up! I was about to lose faith when on a whim I decided to check one last thing even thou I was 99.9 % confident I had done this part of my engine install correctly. I was bored with nothing else better to do so I put my little engine compression gauge on #1 piston, spun the motor to TDC on the compression stroke, looked over at the cute little button a top my distributor, and what do you think I saw boys and girls??? YEP 180 OUT OF TIME!!!! She's been running like a perfectly tuned (and timed) sewing machine ever since. Now to the Transmission...

One other thing i'd like to say is that thanks to this site and the words of wisdom I found here, I never thru parts at my problem hoping for a fix. Instead I tested and did my homework. I'm a much better (shade tree) mechanic for it.

 

I didn't peruse your entire post but try first checking the fuse then unplugging the TCU, if you can shift it manually, there is the problem.

 

A thought...something to rule out..are you sure the Transfer Case is not the issue? (IT has a neutral). There might be other reasons for the 2 wd light to stay on...but the linkage being off or wrong could be one of them. I'm assuming you do have the rear driveline in. I believe if she won't go period, the lectrnics are not THAT problem.

 

Fuse was good but I sprayed it out with electrical cleaner and put a new fuse in anyway. I unplugged the TCU and no fix.
I shifted the transaxle thru its gears but the 2H light never went out. If its stuck in neutral, How do I get it shifted back into 2H?

 

When you move the TC shift lever does it actually do anything you can feel or just flop around?

 

Sounds like the tranny is junk or the t case linkage isn't hooked up and its stick in neutral

 

The TC and drive shifter moves as normal but there was no change when moving it to 4H/4LO. I felt very little resistance like what I'm use to on my 90 Cherokee but no flopping or falling out of gear.

 

I'm not sure how to zero in on it. Radi sometimes shows up late PST. If you loosen a trans cooling line and it doesn't leak maybe there is no pressure? Also can you physically see/rule out that the transfer case linkage is really moving the TC position? I forget exactly the layout...Again, your rear drive-line is in? I'd check that TC linkage, preferably with someone moving the lever while I watch from underneath.


I'm going near my barn, I'll take the camera and photo the shaft of one I have there.

 

Both front and back drive lines are in. And the linkage looks like all is there and connected. Ill have some help with it tomorrow to check if its actually moving the TC. I did see that the 3-4 colored vac lines to the TC are connected but no clue if they work. Ill test those tomorrow along with the cooling lines.

 

Oh and thanks all for the help!! It's greatly appreciated.

 

if you put it in gear and rev it up, does it move?

 

Nope. Ive tried that in every gear and there was no detectable movement.

 

with the t-case shifter in 2hi, is the lever on the t-case all the way forward? it should be...

one that is ruled out, we can go from there. i hate to ask, but you did put the torque converter bolts in, right?

 

I'm getting an early start on it tomorrow and will check the shifter position first thing and let you know.
I had my local auto shop mount the engine/transmission together so I don't have a answer for the bolts. It went straight from where I purchased it to the shop to have the motor put in. I do know that the converter was on the tranny but nothing beyond that.

 

Try using an adjustable wrench to change the transfer case gear/ It kinda sounds like the linkage is messed up