Transmission help

[rednecksafaris]

Good afternoon,

I need some help with my 32RH transmission. I have a 2001 TJ with the 4.0 and an automatic transmission. It started acting like the torque converter clutch solenoid was going bad, So I changed it along with the filter and the fluid. This did not solve the problem. I decided to replace the torque converter and rebuild the transmission. I know...everyone is going to say quite a big leap from a solenoid to a rebuild, but I can't afford to take it in so I have to do all the work myself. Anyway, I pulled it out and replaced the all the clutch discs and all of the seals and o rings. Everything looked really good so I was expecting for everything to go smoothly with the reinstall. Now that everything is back together and back in the Jeep it does not move in any forward gears. It will move in reverse. It will also move when I have the transfer case in 4 low. I have checked and rechecked all of the shift linkages and nothing solves the problem. I have both drive shafts off and when I start the jeep with the t case in 2h and the trans in neutral both drive shafts spin. What the heck is going on. What did I screw up. Any help would be greatly appreciated as I have been working on this for over a month and this is my only vehicle. thank you.

 

[CMBD]

What was the original issue?

Air check it before re installing the valve body?

Pressure tested it now that its back in?

 

[hear]

First off, congrats on having the sack to take on an automatic transmission rebuild. You have joined a very elite club.

Reverse does not use the front clutches, whereas all the forward gears use the front clutches, so my first guess would be that there you're not getting pressure to them. Given that you rebuilt it, I'd be looking at the piston seal on that drum. I can't remember if that one specifically has a taper on it, but it's possibly in upside down or not seated properly. I would drop the valve body & do an air check to see if you get the "thump" of the clutches applying, and then also listen for excessive blow-by. Also, did you check your clearances on those clutches after you put in the snap ring? It's possible you have too much play there. Lastly, did you replace the sealing rings & bushings too?

With both shafts out, it will spin due to fluid coupling between the input & output sections. This is not indicative of a problem.

 

[CMBD]

First off, congrats on having the sack to take on an automatic transmission rebuild. You have joined a very elite club.

Reverse does not use the front clutches, whereas all the forward gears use the front clutches, so my first guess would be that there you're not getting pressure to them. Given that you rebuilt it, I'd be looking at the piston seal on that drum. I can't remember if that one specifically has a taper on it, but it's possibly in upside down or not seated properly. I would drop the valve body & do an air check to see if you get the "thump" of the clutches applying, and then also listen for excessive blow-by. Also, did you check your clearances on those clutches after you put in the snap ring? It's possible you have too much play there. Lastly, did you replace the sealing rings & bushings too?

With both shafts out, it will spin due to fluid coupling between the input & output sections. This is not indicative of a problem.

You ever mess with line pressure adjustment?

Didn't know this was a thing till after some reading this afternoon.

Low line pressure causing no forward gears with reverse only.

 

[hear]

I haven’t….it’s involved and something of a crapshoot. You need to first run the pressure tests, then drain the fluid, turn the screw, re-fill, and re-test. Then likely lather, rinse, and repeat.

You’ve got me questioning what I know, but I thought reverse took like 3x the line pressure, so if reverse is there it would not indicate low pressure….but I’ll have to check to be sure.

No front clutches seems more likely, BUT while he says he has no forward gears what he actually means is that he doesn’t have 1st, since w/o 1st you can’t verify you have 2nd or 3rd.

I would air check it before I did anything else. It would help to know if he touched that screw as part of the overhaul. I haven’t seen any videos where they go over line pressure, and even the ATSG manual doesn’t go into much detail around it.

 

[CMBD]

Sounds fun

I bet its set from the factory and no one ever messes with it. But I could see if you took it apart not knowing what it is, and didn't put it back to the right dimension, you could have a problem.

Would definitely air check before I pulled it again. Maybe a rear clutch issue? Looks like its used in all forward gears, but not reverse.

Im sure you have this book marked, but I forgot about this gem. This is 32RH tech gold

https://wranglertjforum.com/threads/sonnax-article-on-the-32rh-common-problems.24165/

This is a good read on another forum.

https://www.wranglerforum.com/threads/32rh-auto-transmission-build-tips-and-tricks.671593/#replies

 

[hear]

Sounds fun

I bet its set from the factory and no one ever messes with it. But I could see if you took it apart not knowing what it is, and didn't put it back to the right dimension, you could have a problem.

The screw is in a metal plate that separates from the bracket when you tear down the valve body. There is usually some sort of locktite on the screw...it doesn't want to turn on it's own. And unless you had a burning desire to literally tear down every last thing so no two parts were touching, it's doubtful you would adjust it at all. That's my experience anyway.

Those other articles are filled with good info, but I think occam's razor applies here.

 

[rednecksafaris]

Thank you guys for the advise and your knowledge. I don't know what line press is and with my very limited knowledge of automatic transmission I only replaced the clutches and some seals and orings. I am going to run the air tests and see if I can hear the thud. Thanks again for pointing me in a direction to start looking.

 

[hear]

Perfect. I've probably spent more time in these transmissions than anyone else here (apologies to any lurking tranny experts), and I've never messed with the line or throttle pressure screws. If your transmission was fine before, I'm hesitant to think any sort of fix would involve adjusting the pressure. But I'm wrong all the time and am probably wrong here too. But if you didn't touch it, we should definitely focus elsewhere.

Run the air check, video it, and report back. Wear safety goggles....if you accidentally air check the accumulator, you'll be seeing red. Literally.

 

[BobTJ]

Perfect. I've probably spent more time in these transmissions than anyone else here (apologies to any lurking tranny experts), and I've never messed with the line or throttle pressure screws. If your transmission was fine before, I'm hesitant to think any sort of fix would involve adjusting the pressure. But I'm wrong all the time and am probably wrong here too. But if you didn't touch it, we should definitely focus elsewhere.

Run the air check, video it, and report back. Wear safety goggles....if you accidentally air check the accumulator, you'll be seeing red. Literally.

I posted this on another thread but it's an old one and you claim some expertise on the 32RH so here goes:

I'm working to resolve TCC not locking problem on my 1998 with 32RH. I've verified 12V at the TCC clutch solenoid connector on the tranny with ignition on. I've verified wire continuity from the PCM connector to the tranny connector. So external wiring is good. Checked resistance through the lockup solenoid: 30 ohms...should be good. So either the PCM is not taking the solenoid to ground or solenoid or TCC is bad.

My next planned troubleshooting step is to disconnect the tranny connector and use a wire piercing probe to see if the PCM provides ground continuity in the connector wire coming from the PCM. If yes, problem is either the solenoid or the TCC. If no, then I'll need to look at the PCM and/or TCC lockup inputs to the PCM.

My questions:
1) Does my troubleshooting plan and logic make sense?
2) There are no stored DTCs that showed up with a scan. Understand that the PCM looks for RPM change when it commands TCC to lock. If the TCC is not locking, shouldn't there be one?
3) Only mod affecting speedo accuracy is I have 33" tires. Speedo is off only a couple mph. I wouldn't think should cause problems. Anybody know?
4) I mentioned that I read good resistance through the solenoid coil. Anybody ever seen where the solenoid can be good electrically but fail to move mechanically or fail to change fluid flow due to debris/plugged up?

 

[hear]

1) Does my troubleshooting plan and logic make sense?
2) There are no stored DTCs that showed up with a scan. Understand that the PCM looks for RPM change when it commands TCC to lock. If the TCC is not locking, shouldn't there be one?
3) Only mod affecting speedo accuracy is I have 33" tires. Speedo is off only a couple mph. I wouldn't think should cause problems. Anybody know?
4) I mentioned that I read good resistance through the solenoid coil. Anybody ever seen where the solenoid can be good electrically but fail to move mechanically or fail to change fluid flow due to debris/plugged up?

1) verifying continuity does not mean you don't also have a short somewhere. At the very least check both wires for continuity to ground. It still won't guarantee that there isn't an issue, but it might help you find one. That was among the problems I had. I'm a big fan of pulling the entire lower harness up into the engine bay, de-looming, inspecting/repairing/re-looming. I've never not been rewarded for that effort. Something is always in need of repair in a 27 year old harness.

2) I can't account for no codes, it threw one for me. The PCM is a mystery wrapped inside an enigma. It would be nice if there were a virtualized version of the PCM, where we could send in common scenarios as inputs and see what the outputs look like. Although I guess with the right bit of arduino programming, you could probably just use the actual PCM and have the scenario inputs be virtualized... but I digress.

3) I'm also running 33's with the OEM speedo gear, this shouldn't be an issue with the TCC

4) My solenoid wiring inside the transmission had one of the wires worn bare (I think it had been rubbing against the sun shell). Depending on how I had that plugged in (the plug at the back of the trans fits either way), it could work OR it could blow the fuse...if I had it plugged in such that the bare wire was the one that had the 12V on it. It was grounding out against something in the transmission. I had to remove the valve body to solve that one.

 

[BobTJ]

1) verifying continuity does not mean you don't also have a short somewhere. At the very least check both wires for continuity to ground. It still won't guarantee that there isn't an issue, but it might help you find one. That was among the problems I had. I'm a big fan of pulling the entire lower harness up into the engine bay, de-looming, inspecting/repairing/re-looming. I've never not been rewarded for that effort. Something is always in need of repair in a 27 year old harness.

2) I can't account for no codes, it threw one for me. The PCM is a mystery wrapped inside an enigma. It would be nice if there were a virtualized version of the PCM, where we could send in common scenarios as inputs and see what the outputs look like. Although I guess with the right bit of arduino programming, you could probably just use the actual PCM and have the scenario inputs be virtualized... but I digress.

3) I'm also running 33's with the OEM speedo gear, this shouldn't be an issue with the TCC

4) My solenoid wiring inside the transmission had one of the wires worn bare (I think it had been rubbing against the sun shell). Depending on how I had that plugged in (the plug at the back of the trans fits either way), it could work OR it could blow the fuse...if I had it plugged in such that the bare wire was the one that had the 12V on it. It was grounding out against something in the transmission. I had to remove the valve body to solve that one.

1) On the discussion about wiring, I'd think if I had a short in the 12v wire, I'd blow fuse 11. If I had a short on the ground wire, the TCC would lock. Neither of these is happening. Continuity just shows me that a wire is not broken/open. Agree?
2) Agree that no code is a mystery but this discusdion generated a "what if" question in my head... what if there is a fault in one of the inputs that PCM uses to output TCC lock. Maybe if PCM never commands TCC lock due to input conditions, then maybe it won't throw the code since TCC lock was never commanded in the first place. This might be a clue.
3) Thanks for the confirmation.
4) I tried forcing the TCC solenoid to operate by ignition on and grounding pin 11 in the white PCM connector. I thought I might be able to hear the solenoid click with the pan on and filled with fluid. I heard nothing. But not sure what's reasonable to expect. Maybe this is not a good test.

I think I'm going to get a piercing probe and see if the PCM ever takes the solenoid to ground as my next step.

 

[hear]

You'll never hear the solenoid click that way. I know, I've tried.

For #2, i might just wire up a test light that you can see while driving, or maybe even easier to just jam your test leads into the plug and tape them in place. You'll read nothing until the PCM tries to lock the converter, then you'll read 12V. If I was going to backprobe anything, I'd probably try B11 right at the PCM. I assume you've already verified you have 12V on the other leg with the jeep running?

*B11 is what it is on a 97, anyway.

 

[BobTJ]

Yes, I have 12V at the tranny plug when the ignition is on. Thanks for the confirmation about not hearing the solenoid with the pan on. I'll do the test light or continuity check on the ground wire next. I ordered a wire piercing probe from Amazon and I think I can tap the wire going to pin 11 of C151 for the continuity check. Wondering if I can get a good reliable connection on the tranny connector that won't fall off during a test drive. Thanks for the advice. I'll let you know what I find out.

 

[hear]

Wondering if I can get a good reliable connection on the tranny connector that won't fall off during a test drive. Thanks for the advice. I'll let you know what I find out.

I would just tape the crap out of it no matter what approach you take.

 

[BobTJ]

I would just tape the crap out of it no matter what approach you take.

OK, so did some electrical checks and learned a few things. First, when I tried to run my Jeep with the solenoid connector at the transmission disconnected the check engine light came on a soon as I started the engine up. The DTC that was thrown P0743 which indicates an electrical fault in the TCC. OK, duh, plug disconnected...open circuit...PCM is checking resistance in the coil winding to a tolerance. So, I learned that the PCM is checking the state of the TCC solenoid coil and since there was no DTC or Check Engine light before I unplugged the connector, and since I read 30 ohms resistance in the coil, I think the solenoid coil is good but is the solenoid operating the valve spool? Well, the FSM show another transmission related DTC, 0740, which is looking for engine rpm to drop when the PCM asks for the TCC to lock. So if the spool doesn't shift or if the TCC doesn't engage or slips for any reason, 0740 should be thrown.

I decided to do another test drive being more careful to see if I could detect rpms drop indicating the TCC engagement. I slowly accelerated to 35 mph and then went light on the gas pedal, then went to 40 and light on the pedal, then to 45 and light on the pedal and Wella! At 45 mph, level ground and just enough pedal to maintain speed, saw the tach drop about 200 rpm. Goosed the throttle a bit and could detect unlock and then back to lock at about 45 and light pedal again. The FSM says that it should lock up at 35 mph but I guess 45 is the number on my Jeep.

So I guess after spending a fair amount of time looking for a non-problem, it looks as if the PCM is smart enough to throw a code for just about any way that the TCC can fail to operate. At least on my 1998 32RH, the PCM will do all the work of monitoring the TCC for me.

 

[hear]

Nice troubleshooting work (and reading the FSM, which is usually off limits for people with < 20 posts). So where does that leave us then? TCC appears to be working, that was the original problem, right?

 

[BobTJ]

Nice troubleshooting work (and reading the FSM, which is usually off limits for people with < 20 posts). So where does that leave us then? TCC appears to be working, that was the original problem, right?

Not scared of the FSM. In my youth I worked hands on with leading edge CNC machinery and then in an engineering capacity later in life. So I enjoy pouring over technical documentation, drawings and wiring diagrams and figuring out why machines don't work or if they will work.

Original problem?? Well, I'm pretty sure that the output seal on my tranny is leaking. This is a new vehicle to me and I don't know the history. With 150K on the odometer, burnt smelling ATF and a bit of a hesitation after cold start going into reverse, I was trying to get a good idea of the overall tranny condition before I spent a weekend replacing the output seal. So I guess I was trying to test all the transmission functions that I could - i.e. looking for trouble - before I decided to take out the T-case and replace the seal myself or take the Jeep into a transmission shop if I thought it might need expert care. Other vehicles that I've had seemed to be much more obvious when the TCC lock would occur. I had a Ford pickup where I could tap the brake - TCC unlock, let go of the brake - TCC lock. The Jeep fooled me on a test drive.

Now that I'm more convinced that the tranny doesn't have serious internal problems, I think I will drop the pan and change the filter and ATF and go from there. I'll get around to the seal replacement later on when I have time.

Thanks for the assistance.

 

[hear]

If you're going to drop the pan, I would recommend getting the deeper pan with the drain plug, and if you're doing that then also having a fitting brazed in to allow for a temperature gauge. And then a lube locker for the gasket.

When I was in HS we had a really advanced CAD lab (considering the year). I had an opportunity to go straight from HS doing CNC stuff but my parents wouldn't let me. Annoying at the time, but the right decision in hindsight (for me, anyway).

 

[BobTJ]

If you're going to drop the pan, I would recommend getting the deeper pan with the drain plug, and if you're doing that then also having a fitting brazed in to allow for a temperature gauge. And then a lube locker for the gasket.

When I was in HS we had a really advanced CAD lab (considering the year). I had an opportunity to go straight from HS doing CNC stuff but my parents wouldn't let me. Annoying at the time, but the right decision in hindsight (for me, anyway).

What is the purpose of the deeper pan? I was thinking about adding a drain plug to my existing pan. It's a weld-on plug that doesn't extend inside the pan at all.