I am looking at a 97 TJ 4.0 with an automatic transmission. The works fine sometimes shifting through all the gears and then it will get to where you have to shift everting manually. All the gears still work good it just will not shift itself.
97 TJ automatic does not always shift itself
- Thread starter cotreyno
- Start date
This is probably a valve body problem. Whether or not you use D or shift through the gears manually, the same clutches & bands are in use. But if you use the manual shifting there is a different valve body circuit in use.
Have you tried to really really really wind up first gear to see if it will shift eventually? Sometimes a description of it not shifting is really a case of it not being able to complete the shift to 2nd gear, and you have to make it want to be in 3rd gear to complete a shift. But this is also because there is a problem applying the intermediate band, but I doubt this is the case because you have manual 2nd. So we can conclude that the band & apply servo are working, but maybe we can isolate that the manual 2 circuit is the culprit. (which isn't to say that I suddenly have some silver bullet solution for you).
In either case, valve bodies are where the real black magic is. I've yet to find anyone who can do any sort of real diagnostic. I think beyond doing what I describe above (which would only serve to possibly point to where the problem is, solving it from there would still be challenging), I would find a used valve body on ebay and replace it. That's an easy job, although I do hate just throwing parts at a problem. There are a couple of us who know the 32RH pretty well, but I don't know that any of us really & truly understand the valve body.
Have you tried to really really really wind up first gear to see if it will shift eventually? Sometimes a description of it not shifting is really a case of it not being able to complete the shift to 2nd gear, and you have to make it want to be in 3rd gear to complete a shift. But this is also because there is a problem applying the intermediate band, but I doubt this is the case because you have manual 2nd. So we can conclude that the band & apply servo are working, but maybe we can isolate that the manual 2 circuit is the culprit. (which isn't to say that I suddenly have some silver bullet solution for you).
In either case, valve bodies are where the real black magic is. I've yet to find anyone who can do any sort of real diagnostic. I think beyond doing what I describe above (which would only serve to possibly point to where the problem is, solving it from there would still be challenging), I would find a used valve body on ebay and replace it. That's an easy job, although I do hate just throwing parts at a problem. There are a couple of us who know the 32RH pretty well, but I don't know that any of us really & truly understand the valve body.
OP
is there any chance it could be a wiring issue i have not actually got my hands on this jeep yet I am going to pick it up this weekend. The guy said he thinks its something to do with the wiring. He said he drove it for five days and it shifted fine and then all of a sudden it would not shift. But he could manually go through all the gears.
This is a (nearly) fully hydraulic controlled transmission. The only electronics involved are the neutral safety switch and the torque converter lockup solenoid. Neither of which are your problem. If you simply unplug the TCC from the back corner of the transmission, the only thing that will happen is you'll no longer get that TC lockup in 3rd gear, and you'll likely get a P0704 code.
If you unplug the NSS you'll have a new set of problems.
If you unplug the NSS you'll have a new set of problems.
He is feeding you a bunch of bullshit so he can get a better price. Something is wrong inside the trans.
OP
Ok I will probably try a filter and fluid change first maybe the pressures are off or some trash floating around for some reason. What type of fluid is recommended???
OP
oh snap, if it's an AW4 ignore everything I said. It is electronically controlled.
Can you get a pic of the transmission pan & post it here? Let's figure out what we're working with. I assumed you had the stock tranny.
OP
There are at least 2 transmissions that could be, but a picture would settle the debate and then we can advise you.
OP
OP
so I just talked back to him and he says he leaves the tcm unpluged and shifts through 3 gear and does fine. He plugs up the ecm and it shifts find sometimes and other times it will not shift out of first. But with it plugged up it shifts into overdrive I guess which is fourth gear.
OP
I am back on this It defiantly has the AW4 transmission. I found some wire on the grey plug coming for the TCM on the transmission side they had melted to the exhaust I fixed all of them and it still would not shift. I was unsure if the TCM may have been damaged from the wires melting so I bought a new one and installed and it still does not shift. I can unplug the TCM and it will shift Manually. I tested battery voltage and ignition voltage and ground to the TCM itself and that all checks out. Those are wires 24-25-26 on the 26 pin connector to the TCM. Where do I go from here?? I also replaced the TPS sensor. All the wiring seems to look got on the harness that was made to go from TCM to the black and grey plugs and the wires that were spliced into the PCM look good.
Your best bet is probably to visit the NAXJA forum, they will have way more expertise in the AW4 than we will. I’ve rebuilt several of them, but it’s one thing to put the pieces together. It’s a whole nother thing to make a computer control it properly.