1981 Torque Converter Lockup
New to the site! Looking forward to the collaboration! Need some help!
Sorry if this has been discussed - don't really see what I am looking for, but may have missed it. If so, would appreciate someone sending me the link!
1981 - I removed the ECM - Holley 4160 - Vacuum Dist. - but not sure what to do about the Torque Converter Lockup.
Can someone please explain to me what a torque converter lockup is, how it works, and why I need it. Still not sure what to do here since removing the ECM.
Thanks much!
This will make the car shift properly as long as you have the kick down cable geometry set up properly on the carburetor. Many speed shops sell this kit.
Good luck and be sure to get the kick down cable properly set or you can burn up a transmission fairly quickly.
Other members will have other options and chime in, but this kit has been great for me and my customer's cars.
Welcome to the site!
Last edited by CMD1; Apr 13, 2019 at 10:22 PM.
Lockup feature is built into the converter. It is a hydraulic clutch which, when applied, connects the input side of the torque converter to the output side, so that the converter becomes a direct-drive device with no hydraulic losses. But, that clutch is not sturdy enough for much torque...maybe 200 ft-lbs...max. Overdo it and the clutch fails....or the converter fails.
Lockup is supposed to drop out (go back to hydraulic converter mode) when going up a hill or applying more than so much accelerator movement when in high gear. The ECM managed that so the lockup system would survive. Oh.. BTW....running that transmission without applying lockup is also not a good idea. When not using lockup, the converter generates more heat that expected and, if left that way for long highway runs, can fail the transmission. So, lockup NEEDS to be applied when called for; and it NEEDS to be dropped when significant acceleration is required. That means [for most folks] a lockup controller should be installed to correctly manage the lockup clutch.
That's what it is: that's what it does; that's how it works; and that's what it needs. What you decide to do will determine if your transmission will live--or die prematurely.
Last edited by 7T1vette; Apr 14, 2019 at 12:46 AM.
The main thing is to make sure your TV cable is adjusted correctly or you will kill your transmission in a heartbeat.
Thank you, thank you, thank you. This is the most extensive explanation I've seen yet on what the lockup does and how it works.
I will ensure my TV cable is connected correctly and install an external kit.
Thanks again so much for taking the time, sincerely appreciated!
Thank you, thank you, thank you. This is the most extensive explanation I've seen yet on what the lockup does and how it works.
I will ensure my TV cable is connected correctly and install an external kit.
Thanks again so much for taking the time, sincerely appreciated!
Not having it drop out can be a dangerous thing in some unusual circumstances. Let "Bubba" be Bubba and throw a toggle switch in there. Not for me....
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Not having it drop out can be a dangerous thing in some unusual circumstances. Let "Bubba" be Bubba and throw a toggle switch in there. Not for me....
Hope you don't mind one last question, I could probably Google this but.....I was hoping not to have to bust into the tranny. Are you aware of an external controller that I can throw in my Vette to "mimic" the ECM in this case.
Hope I'm asking the right question...
Thanks again for your time!
Hope you're both still there and doing well and don't mind answering a few more questions about this torque converter lockup.
- Possible you could help me identify my tranny. I am assuming it is the TH350C as that has the lockup and the TH350 does not. Want to make sure I am getting the right lockup kit. Pretty sure I don't have the 2004R or the 700-R4. Is this correct? Need more info?
- In my shop manual, I am assuming that the TCC solenoid is the torque converter lockup solenoid. Is this correct?
- I believe this solenoid is actually in the tranny, is this correct?
Ready now to address this lockup.
Thanks in advance!
Yes, agreed, the 4-speed tranny seems very appealing. Might also go with the manual transmission.
In the meantime, need to get this torque converter working right on the 3-speed I have. I ripped out the ECM when I put the crate motor in, but left the tranny alone. All the vacuum and linkage to the transmission is good I believe, just need to finish this TCC.
Good luck with your transmission switch.





i used the B&M kit when i did the 700r4 into my '72 many years ago.
also added a brake pedal dropout switch and a vacuum switch dropout for when under hard load.
Wow, from Adelaide, that's awesome. Was down there back in 2000 when I worked in rapid prototyping.
Yeah, that's exactly what I am looking for: a kit for a TH350C where I don't have to go into the tranny, has the vacuum and break dropout, engages either via speed or vacuum, and a switch just for when I feel like it.
Haven't found that yet, but will keep looking.
Thanks for responding.















