32RH torque converter lockup bypass?

[GASnBRASS]

Checking to see if anyone knows if the torque converter circuit from the PCM can be bypassed with a "fake" circuit to keep the check engine light off? The PCM completes the ground side of the circuit for the TC lockup, but I'm not sure if the PCM monitors engine RPM to verify if it's engaged.

(Looking to install a reverse pattern manual valve body and they all seem to disable the TC lockup.)

 

[Jerry Bransford]

The engine rpms are monitored by the PCM to verify that the torque converter locked up. You'll get a CEL if those rpms don't drop when the PCM expects them to after commanding the solenoid to lock the torque converter.

Your transmission will run hotter and you'll get worse mpg if you don't allow the TC to lock, I wouldn't do anything to prevent that from happening.

 

[GASnBRASS]

I'd be curious if the TC lockup monitor can be disabled with one of the advanced software tuners.
Or I will have to dig into the flow circuits and determine if it can be manually engaged when needed.

 

[Jerry Bransford]

What is it about reverse pattern manual valve bodies that you find appealing enough to be willing to go to all that extra work that will also likely end up defeating the lock-up ability for the torque converter? I understand what they do, I just don't see a compelling reason to use one in a TJ for the uses common in this group.

 

[GASnBRASS]

It's not malfunctioning, I simply have not cared for how the 3 speed shifts from day one. Adjusting the kickdown has not helped, and rather than mess with governor weights or different VB plates I'd rather just gain total control of when it shifts. As much as I'd like a manual, the jeep transmissions feel notchy and I absolutely despise it's mushy hydraulic clutch.

With a RMVB I can easily slip between first / neutral / reverse when offroad, and still retain the very low creep that an auto allows. If it utilizes a front band engagement it will have engine braking as well, and frankly I want a little more interaction to the driving experience (it's a popular mod for Mopar street rods and guys seem to love it). Only snag I seem to keep running into is the TC lockup.

 

[Jerry Bransford]

I dunno, I shift 1-2-1-R-1-2-R all day on the trail without any problem and the torque converter doesn't come into play at all then. The ONLY time the torque converter locks up is when you're at a cruising speed on the street or highway. I converted to that same transmission, the 32RH, in my previous TJ and it shifted great... to me at least. Maybe your kickdown (TV) cable length really isn't adjusted correctly, hard to say without being able to drive it. Being adjusted too tightly will make it shift abruptly and harshly. Being too loose will make it much harder if not impossible to engage passing (2nd) gear when cruising.

 

[GASnBRASS]

I'm not going to debate whether it should be done or not, I have my reasons for doing the mod.
Just trying to gather info about my two questions that I cannot answer using the FSM or google search.

 

[Raul G]

I dunno, I shift 1-2-1-R-1-2-R all day on the trail without any problem and the torque converter doesn't come into play at all then. The ONLY time the torque converter locks up is when you're at a cruising speed on the street or highway. I converted to that same transmission, the 32RH, in my previous TJ and it shifted great... to me at least. Maybe your kickdown (TV) cable length really isn't adjusted correctly, hard to say without being able to drive it. Being adjusted too tightly will make it shift abruptly and harshly. Being too loose will make it much harder if not impossible to engage passing (2nd) gear when cruising.

Hello Jerry, you seem to know more about the TCC. My Jeep 4.0 3 speed auto used to shift ver well the tcc would engage at highway speed but after replacing the oil it started to act up. It will not engage the tcc at highway speed. And shifts at higher rooms than normal. There was also a short down in the transmission in the connection of tcc solenoid time the harness connector. Could it be that the solenoid is toast and may need replacement? Although I have no codes.

 

[Jerry Bransford]

Hello Jerry, you seem to know more about the TCC. My Jeep 4.0 3 speed auto used to shift ver well the tcc would engage at highway speed but after replacing the oil it started to act up. It will not engage the tcc at highway speed. And shifts at higher rooms than normal. There was also a short down in the transmission in the connection of tcc solenoid time the harness connector. Could it be that the solenoid is toast and may need replacement? Although I have no codes.

Did you refill it with the correct ATF which is strictly ATF+4? If the bottle didn't say ATF+4 in big letters on the front label it was the wrong type of ATF. A bad solenoid could certainly be the reason for the torque converter to not be locking up. The 32RH will not generate any codes, it is strictly hydraulic other than having an electric solenoid used to lock up the torque converter. It's possible to see a 37 Diagnostic Trouble Code which indicates the computer did not see the expected drop in engine rpms after it signaled the solenoid to lock the torque converter. That would set a Check Engine light but it would only happen at cruising speeds.

 

[Raul G]

Did you refill it with the correct ATF which is strictly ATF+4? If the bottle didn't say ATF+4 in big letters on the front label it was the wrong type of ATF. A bad solenoid could certainly be the reason for the torque converter to not be locking up. The 32RH will not generate any codes, it is strictly hydraulic other than having an electric solenoid used to lock up the torque converter. It's possible to see a 37 Diagnostic Trouble Code which indicates the computer did not see the expected drop in engine rpms after it signaled the solenoid to lock the torque converter. That would set a Check Engine light but it would only happen at cruising speeds.

Thanks, jerry I am not sure if it was atf+4. I will take a look at my receipts. Incase it was not the correct atf, would I just drain it and replace it? See if taht may be the problem.

 

[Jerry Bransford]

Thanks, jerry I am not sure if it was atf+4. I will take a look at my receipts. Incase it was not the correct atf, would I just drain it and replace it? See if that may be the problem.

Yes it's ok to just drain and refill it with the correct ATF+4. Remember to always refer to the owner's manual for advice on which lubricants to use, that way you wouldn't have let them use the wrong ATF if that's what they did.

 

[Raul G]

Yes it's ok to just drain and refill it with the correct ATF+4. Remember to always refer to the owner's manual for advice on which lubricants to use, that way you wouldn't have let them use the wrong ATF if that's what they did.

Thanks truly appreciate it!

 

[thomat65]

I'd be curious if the TC lockup monitor can be disabled with one of the advanced software tuners.
Or I will have to dig into the flow circuits and determine if it can be manually engaged when needed.

I'm interested to hear which route you ended up taking?

 

[Recycledteen]

Good morning Jerry, I like you have my precious 99tj with a 32rh in it but have been having some problems with it.
I have a 1999 TJ, 4.0 with 32RH auto trans. Having a problem where it seems like the torque converter is trying to lock up and not release when stopped and in gear. Also it happens while on the trail if I go over a bump and let off the gas, it seems to drop RPMs and then die. Also this will happen at normal idle RPM, when in drive and foot on the brake, the RPMs will drop really low and then come back to normal RPMs. Sometimes the engine dies all together and when this happens, I have found the gauges' hands will drop to nothing and the engine will turn over but will not crank. Also you can't move the jeep, it seems frozen to the ground. After trial and error we have found that if you move the jeep any at all, even an inch, it seems to release the tranny, torque converter and engine and the jeep will roll easily and immediately start. I can keep this from happening by keeping the idle a little higher than normal by 2 feet driving and shifting into neutral when coming to a stop. When on the road it shifts great, goes through all the gears fine, and no slipping at highway speed that I can tell.
Not sure what to do with this problem but one guy on the trail suggested installing a switch to manually lock/unlock the torque converter. Don't know if I want to do that unless there is no other option. What is causing this and what can I do to fix this?

 

[astjp2]

Ever fix your problem?