What would cause my torque converter to finally start locking?

[LittleTankTJ]

Until recently it seems like my torque convert hasn't been locking up.

What's been done since it has started locking up is:
Oil change
Transfer case oil change
Spark plugs
Sat for 2 weeks because of quarentine

None of these seem like they would have cause the torque converter to start locking up. But what do I know? If none of these are what did it, what should I look for to find what did and keep it from not locking up?

It's a 4.0 with 32RH and standard NP231, 33 inch tires and 4.10 gears.

 

[Goatman]

If your torque converter wasn't locking you would have replaced the transmission by now. Without locking up the input shaft wouldn't maintain positive engagement with the engine. Overheating and slippage should have destroyed the trans.

 

[John Scoggins]

Until recently it seems like my torque convert hasn't been locking up.

Have you gotten any codes, like P0740 and/or P0743?

 

[Cross-Threaded-06TJ]

If you are referring to the Torque converter clutch. It may be the solenoid is sticking and wasn't working and now it is. I would just keep an eye on it and if it stops again, look into replacing the solenoid. Or making sure it is being commanded on when it is not locking up. That will require a scan tool and possibly a friend to go on a road test with you.

The Torque converter clutch is the only electronic component in your 32RH. So diag will be pretty simple. For now if it is working go with it, maybe drop the pan and do a service also. Maybe replace the solenoid while the pan is off if you want?

 

[LittleTankTJ]

If your torque converter wasn't locking you would have replaced the transmission by now. Without locking up the input shaft wouldn't maintain positive engagement with the engine. Overheating and slippage should have destroyed the trans.

Maybe something else is in play. But my 3rd gear rpms when not accelerating are lower than they used to be. The transmission fluid still looks good.

Have you gotten any codes, like P0740 and/or P0743?

None of those codes. That's what's so confusing.

If you are referring to the Torque converter clutch. It may be the solenoid is sticking and wasn't working and now it is. I would just keep an eye on it and if it stops again, look into replacing the solenoid. Or making sure it is being commanded on when it is not locking up. That will require a scan tool and possibly a friend to go on a road test with you.

The Torque converter clutch is the only electronic component in your 32RH. So diag will be pretty simple. For now if it is working go with it, maybe drop the pan and do a service also. Maybe replace the solenoid while the pan is off if you want?

Would the solenoid sticking cause a computer code though?

It may be that I'm more on it looking at my rpms as of late instead of the temp and oil pressure. Could a sudden decrease in friction or drag somewhere make it so the ecu doesn't think the converter has to be disengaged?

Thanks for your input everyone!

 

[Cross-Threaded-06TJ]

Maybe something else is in play. But my 3rd gear rpms when not accelerating are lower than they used to be. The transmission fluid still looks good.


None of those codes. That's what's so confusing.


Would the solenoid sticking cause a computer code though?

It may be that I'm more on it looking at my rpms as of late instead of the temp and oil pressure. Could a sudden decrease in friction or drag somewhere make it so the ecu doesn't think the converter has to be disengaged?

Thanks for your input everyone!

It would set a Fault if the solenoid has an electrical Open/short circuit. But, the TCC solenoid can stick mechanically and not set faults. I worked in a Transmission shop for years that had a solenoid test machine and the Chrylser TCC solenoids sometimes would start to stick mechanically once hot.

It really doesn't sound like this is what yours is doing. I think you are just paying more attention to it and noticing it working.

 

[LittleTankTJ]

It would set a Fault if the solenoid has an electrical Open/short circuit. But, the TCC solenoid can stick mechanically and not set faults. I worked in a Transmission shop for years that had a solenoid test machine and the Chrylser TCC solenoids sometimes would start to stick mechanically once hot.

It really doesn't sound like this is what yours is doing. I think you are just paying more attention to it and noticing it working.

Kind of like when my stereo went out and suddenly the engine made more noise.