PO741 still trips after solenoids & 4th hub

[3repete]

? I still have the PO741. "Torque converter clutch not locking up" Though my trans shifts nicely.

There is also a problem with my car giving a ratcheting sound over 4500 rpm. The ratcheting was at 4000 so I tried the coil packs from my good L67 which moved the noise up to 4500 and improved my acceleration. So I will be getting some coils.
I had already put in fresh NGK wires and iridium plugs.
I'll put the car up in the air at work and see if there's a rattle inside the catalytic converter, suppose it could be that. If I need a cat and want to pass emissions should I do OE? Or can I do a free flow converter and a cat fake mod? I'd rather have the high RPM punch that my other rusted car has.
I'll work out the ignition, I'd think. And it may help with the TCC code, but I don't expect it to.

The question on this post though is for the trans. Should I check the valve body for issues relating to the PO 741?
In the Sonnax literature it suggests an 84754-34K kit which repairs the TCC regulated apply valve. Only issue I have is that the tool costs almost as much as a rebuilt valve body.
I'm concerned about whether to find a shop to check my VB and hopefully guide me, buy the $300 to $400 reamer, or just buy a 47,000 mile crash victim complete trans that i have access to for $450.
Nothing seems certain!
Maybe I can find a trans repair shop that will look at my VB for me. I'm out of my skill area here.
It is such a project to R&R the valve body that I only want to do that one more time.

Oh and don't recommend robbing parts off the old car, it has 238K miles on it and I have a buyer. Plus it's mid winter and I can only tear down one car in my garage space.

 

[Transman304]

Are you reaching 4th gear? There are a couple company's that make VB kits to address this issue and others that don't require any reaming. It would be ideal if you could have a scanner attached while driving and take a movie to narrow down other wear areas.

 

[3repete]

Yes, it gets 4th each time. Just doesn't hold lock. I don't have access to a trans scanner, can I scan with a "normal" one? I will see if I can watch it with a good Snap On scanner at work.

 

[Transman304]

Here is a diagram of the lock up system. And the conditions needed to se P0741

Conditions for Running the DTC
* No TP sensor DTC P0121, P0122 or P0123.
* No VSS DTC P0502 or P0503.
* No AT ISS sensor DTC P0716 or P0717.
* No TCC stuck ON DTC P0742.
* No TCC PWM solenoid valve DTC P1860.
* No TCC release switch DTC P1887.
* The engine speed is greater than 500 RPM for 5 seconds and not in fuel shut off.
* The time since the last gear range change is greater than 6 seconds.
* The transmission fluid temperature is 20–130°C (68–266°F).
* The TP angle is 4–35%.
* The TCC PWM solenoid valve is commanded ON for more than 0.5 seconds.
You will need a scanner that can see and record data. Was lock up working before repair?

 

[3repete]

Hi, I'm back. A local trans repair guy I have spoken to in the past said he usually does a rebuilt converter in these transmissions so I did one. It did help. Improved fuel economy and drives well. But now I have the PO 1887 code which indicates torque converter clutch release fail. It appears to point to a failure in electrical parts but MAY be due to a leak in the valve body. I am going to do the external electrical testing. But if any of you have experience with this fault I'd love any input.

 

[3repete]

So here is the rest of the story. I originally had PO 741. For that I did the valve body solenoids, a 4th clutch hub and the internal wiring harness. After that I still got PO 741, TCC fail. So then I did the converter.
From my research it appears I should now check the wiring from terminal U to the pcm. According to the book there are back probe wiring tests.
If I understand it there should be continuity to ground at terminal U with key on-engine off and there should be 12 volts there when the engine runs. There's also a test with the plug removed. If those are correct I should probably get into the valve body where there can be an o ring leak at the TCC switch.
I moved the valves when I had the VB out the first time and none were sticking or sloppy, But I was not aware at that time of this o ring possibility.
If I do remove the valve body should I replace the gasket between the VB and the plate below it? I'd plan to do that.

 

[Transman304]

There is an O ring on the TCC regulator apply valve. It will be blue in color. It can cause the conditions you are describing but you would have seen problems before converter replacement. Just asking when the converter was installed did the turbine shaft O ring get replaced? It will sometimes get damaged when removing and installing converter. Also check the the case connector and harness are not damaged.

 

[3repete]

So I will do the electrical check and if all's good I'll check those pieces. Where's a good place to get the correct o rings?

 

[Transman304]

I don't know how soon you are needing them but PM your address and I will put a couple in an envelope and send them off to you.

 

[3repete]

Very kind of you. I will pay it forward to someone else myself. PM sent.

 

[3800sofine]

see this is the problem with these needy transmissions, you will chase that problem all around until you spend $3000 fixing it. not worth it.
if it's shifting smoothly ignore the code for the TCC clutch.
it only gives a mileage increase on sustained highway speed trips, not in normal average daily driving.
I cut the wire for TCC on mine and my mileage stayed dead nuts the same.
so why go through all the expense and hassle trying to fix it
the old saying, you can't win for losing (money).

 

[3800sofine]

I did an electrical check on all the old solenoids that I had changed in my trans, and they all checked good right in the middle of the specs for ohms.
but when tested with 12 volts, they applied sluggishly and disengaged sluggishly
see you can't diagnose something like that electrically. it escapes diagnosis.
so you have to use common sense and your own intuition.