No TCC lockup with 4L80E
It drives well, all gears work, shifts okay (needs some tuning), but I have no TCC lockup, not even a smidgen.
I'm trying to force lockup with EFILive while driving and nothing! I can hear a very faint click when I turn the solenoid on with EFILive, but it's much much quieter than the shift solenoids. According to the log I took it tried to lock it up on its own too and nada.
Solenoids are all new, no codes, pressures seem okay. I get around 60-70psi at idle warm, and regularly gets around 150psi on the throttle, but I didn't watch the pressure gauge too much.
I hardwired the TCC signal wire (pin S) to a switch to ground it when I want. When I turn it on while driving at lowish throttle nothing happens. But as soon as I increase throttle it starts to grab and the RPMs drop. If I give it enough throttle it will almost totally grab, the TC slip will drop to around ~100 RPM. I did this a couple times to verify my results, hope this didn't do too much damage to the converter.
So it sounds like its a mechanical issue within the trans. Anyone have ideas of where to start looking? I'd like to start with the things that are easy to get to such as the valve body. But I fear it might be the stupid o-ring on the input shaft. Bummer.
It drives well, all gears work, shifts okay (needs some tuning), but I have no TCC lockup, not even a smidgen.
I'm trying to force lockup with EFILive while driving and nothing! I can hear a very faint click when I turn the solenoid on with EFILive, but it's much much quieter than the shift solenoids. According to the log I took it tried to lock it up on its own too and nada.
Solenoids are all new, no codes, pressures seem okay. I get around 60-70psi at idle warm, and regularly gets around 150psi on the throttle, but I didn't watch the pressure gauge too much.
I actually did the dual-feed internally by blocking off the reverse passage in the case, removing the inner seal on the direct piston, removing the seal on the center support shaft, and also drilled a small hole in the outside of the direct drum. I left out the 3-layer plate and used a single layer instead.
There does seems to be many things that could cause this. I'm going to start with things I can access by dropping the pan.
I actually did the dual-feed internally by blocking off the reverse passage in the case, removing the inner seal on the direct piston, removing the seal on the center support shaft, and also drilled a small hole in the outside of the direct drum. I left out the 3-layer plate and used a single layer instead.
There does seems to be many things that could cause this. I'm going to start with things I can access by dropping the pan.
Did you do any mods or tuning to up the pressures? What RPM do you idle at? Mine idles at around 700 RPM.
Based on my testing, I need somewhere around 200psi of line pressure to fully apply the TCC, and probably even more to for it to hold any decent amount of power.
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Did you do any mods or tuning to up the pressures? What RPM do you idle at? Mine idles at around 700 RPM.
Based on my testing, I need somewhere around 200psi of line pressure to fully apply the TCC, and probably even more to for it to hold any decent amount of power.
TCC should work even at minimal line pressure at cruise, which could be as low as 70-80 psi at very low TPS settings.
You may have a converter with a bad lockup seal, bad seal on the input shaft, etc.
The lockup circuit has more potential problem areas than any other circuit on this transmission. It's one of the areas that we've spent the time to make our builds work better than most.
Make sure the o-ring on the solenoid is in place and not damaged.
I also HIGHLY doubt your unit is "fully" rollerized. That's a lot of machining and specialty parts.


