Hays 3/4 Race Twister TCC

[gcp_mn]

I just finished rebuilding a 4L60E with a Hays 3/4 Twister torque converter for my Chevelle. Other than lockup the transmission works great.

I did not remove the pan yet, but I did connect a switch to enable/disable the TCC. The switch also has a LED, which I ran in series with the TCC solenoid. When the transmission shifts into 4th gear, the LED lights, so I know the pressure switch is working and current is flowing through the solenoid.

Unfortunately, I don't notice anything when switching the TCC circuit on/off while cruising in 4th gear. I'm assuming there would be a slight change in RPM when the clutch engages/disengages. Other than pulling the torque converter, is there anything else I can look for in the valve body or the valve under the solenoid?

[Gaz64]

I'd assume a 3/4 race torque converter doesn't have a TCC inside the converter, since the lockup clutch is not designed for high torque. Gary

[Danny Cabral]

I was thinking the same thing.

[gcp_mn]

HAYS TWISTER 3/4 RACE TORQUE CONVERTER, 1984-91 GM 700R4
9.6" diameter torque converter with lockup 30 spline input, 10-3/4" bolt pattern, 3200-3600 RPM stall. PART# 97-1E32Q

[Gaz64]

I did not remove the pan yet, but I did connect a switch to enable/disable the TCC. The switch also has a LED, which I ran in series with the TCC solenoid. When the transmission shifts into 4th gear, the LED lights, so I know the pressure switch is working and current is flowing through the solenoid.

I would think the TCC solenoid would not operate in SERIES with an LED. The solenoid should be in parallel with the LED. Gary

[gcp_mn]

Originally, the TCC wiring went through just the brake switch. I couldn't tell if it was working, so I added the manual switch with the LED. I wired the LED in series to check if the solenoid and pressure switch were working and verify if the wiring was all connected, without having to remove the pan.

[Gaz64]

I think a solenoid will not operate in series with an LED.
If the switch you have has an LED as part of the switch, the LED is in parallel, which is correct.
If you made this setup, and the LED IS in series, change the circuit to parallel. Gary

[gcp_mn]

I apologize for the confusion, the switch LED was only used in series to check the continuity of the circuit. I was trying to do as much troubleshooting without having to drop the pan.

I'm waiting to hear back from Holley to confirm whether or not the torque converter has a clutch in it. If it does then I'll have to drop the pan to see if the solenoid is working and see if the TCC valve in the pump might be stuck. If everything looks good there, my next step would be to pull the transmission and see if the o-ring on the input shaft is damaged.

[Gaz64]

I like your thinking on using the LED for confirming the circuit. You're on the right path. I've seen o-rings cause similar symptoms. Gary

[gcp_mn]

I still have not heard back from Holley. Maybe I should've gotten the TCI torque converter? Customer service would be the same.