Gdawg311

I bought an '87 Wagoneer Ltd a few weeks ago and it recently started having some transmission issues.

I haven't been driving it much, but over the course of the past few weekends it's started acting a little funky. About 2 weeks ago, it started to stumble shifting into second - it would shift up to second, but then seem to stumble at lower RPMs. Once I gave it a little gas, it felt like it finally "got" the gear and would drive just fine. I didn't touch it all week, and then last weekend when I took it out for a drive it refuses to shift up into second at all. Pulling away from a stop, it will accelerate as usual from first except once I hit about 15mph where it usually would shift, nothing happens. If I continue to accelerate it will eventually find third at about 35mph, but I'd rather not run the RPMs up that high more than I need to. Once I'm in third it refuses to downshift when I slow down, and will just bog down in third to the point where it has almost no power, until shifting back into first.

I checked the fluid and it looked pretty high, but that was the same level it had been at since I got it and it shifted just fine when I brought it home.

I'm thinking that this is a solenoid issue, but I'm not entirely sure - anyone with some actual experience have an idea?

boxburn

Are you sure you're getting 3rd at 35mph and not 4th? If it's 4th, solenoid #2 or the wiring to it would be suspect.

Try the manual shift test going 1-2, 3, D. You will only get 1st 3rd and 4th while doing this.

Gdawg311

Honestly I hadn't even considered that it may be jumping straight to 4th... that would definitely explain the lack of power below 35mph. I'd imagine 3rd gear would bog down to some extent, but it's bad enough that I pulled over the first time because I thought I lost power completely.

boxburn

Hopefully your connector is the same as this. I know they changed later on but I don't know if they were the same from day 1.

Grab a multimeter, set it to Ohms and check pins E, F & G against a ground point. You should get around 11-15 ohms on each of them. If you get a high reading or 1/OL (no continuity) on F, that would explain your issues. It would either be the wiring to the transmission or a dead solenoid.

Gdawg311

Thanks for the tip! The couple of videos I found online would've had me pulling the pan off of the transmission and checking the solenoids directly - this is a lot more straightforward.

I'll check them out tonight and let you know what I find. Thanks for all your help!

Gdawg311

Well, I tested all the connections with a multimeter and was getting a consistent 14.5ish ohms across all 3. I checked all of them 2-3 times just to make sure I was getting consistent & reliable results and sure enough, everything reads fine.

Not sure what my next step would be - fluid level is still high and I'm not sure how long ago the filter was replaced. Try dropping the pan and addressing those issues before moving forward?

boxburn

Have you tried the manual shift test yet? If that checks out then the issue is electrical and not mechanical. It is still possible that a solenoid isn't operating correctly even with a good ohms reading but it's worth checking stuff before loading up the parts cannon.

Checking the fluid level is always worth doing but in the words of a wise man on this forum, don't bother changing out the filter, there'll be nothing wrong with it.

Gdawg311

I was hoping to get to the manual shift test last night, but I only ended up getting home around 8/9. I don't have anything going on after work today, so I'll try it out tonight and report back.

Gdawg311

Well, you were dead on in your first post - looks like it's been skipping 3rd and jumping straight to 4th. Drives MUCH better with the TCU disconnected and shifting manually. Plugged it back in just to verify and it's definitely skipping 3rd. Shifts a little hard going back down to 1st and when going in reverse despite me trying to baby it as much as I could, but it's at least driveable now, no revving 1st gear to 35.

I did a little more looking around and tested out the TPS because that seems to be a common problem, and I'm either doing something wrong or it's completely shot. Tested and I'm getting 5V in as I should, but once hooked up and back probed I'm only getting 0.55V at closed throttle and 0.46V at full throttle.

Again, I'm probably doing something wrong when testing it but it's at least worth a shot, and not an expensive part to replace.

awg

I would advise you to check the No2 solenoid is working by providing it with 12V by disconnecting the same plug you tested, and touch a wire from the battery to that terminal. You can hear the solenoid click open & shut from outside the trans case (but you must be close), so need an assistant, or run long wires and do it yrself from under the XJ

If it doesnt audibly click on & off with 12V applied and removed, the solenoid is not functioning, if it does so, the problem may be elsewhere (wire harness, TCM, TPS etc)

boxburn

Agreed with awg.

When it currently tries to go back down to 1st, it's probably trying for 2nd but Sol#2 isn't functioning so hits 1st instead.


As you already know where it is and have already disconnected the TCM, you can try probing the TPS voltage on the TCM connector and see if your readings are any better. At the same time you can see if your solenoid resistances are the same, which would rule out wiring. You could also try awg's suggestion of manually testing the solenoid from the TCM connector.




I've no experience with dealing with the TPS so without digging through the FSM's I couldn't tell you what they should read. I am pretty sure it's one of the sensors that's recommended to replace only with a MOPAR part though, other brands just don't work well. I'm about to be away for the weekend so don't have the time to dig into this much further right now. Hopefully the above is useful though.

Gdawg311

Thanks! I ended up ordering a TPS anyways because it was like $17 - if it doesn't work/isn't the problem I'll just pop the original back in. Worth a shot at the least for the price, and I won't have to worry about it again. Once I get home tonight I'm going to try out the test awg suggested &order a solenoid kit if need be, and I'll try testing the TPS from the TCU as well just to see. Thanks for all your guys' help! I would be completely lost if I hadn't come here.