TH350C Lock-Up diagram

[RodC]

I have a TH350C trans that came out of a 1980 Chevy pickup. It has the two wire plug for the lock-up torque converter. This was the model that was used before the ECM was used to control the lockup. I have read many articles describing the vacuum and electrical system used to control this. Sounds like I need a vacuum govener (NOT the one in the Tranny) and a few other parts to create this.

What I really need is a diagram from the 1980 Pickup so I can order the parts to make this system up.

Summit racing has a kit that will allow you to tap into your spedo and control the point that the torque converter will lock up but I would like to do it a little cheaper if it is possible.

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Rod Childers
'71 C10 Stepside

[Fast68]

toggle switch flip on at aobut 40 or 45 or wherever you cruise at, thne flip off at the speed before when it leaves 3rd back down to 2nd

dunno how much rpm a lockup converter actually knocks off, but it aint much

[This message has been edited by Fast68 (edited 12-20-2001).]

[RodC]

Actualy I have an interlocked relay with a pushbutton that is disconnected by a NO connection on my brake light switch, but I would like to make it right. It is a PIA to try to rember it all the time.

[Boog]

I have an '80 trans with lockup in my 69 I'd like to hook up the right way too.Looking at my 85, there are actually two vacumn switches on the firewall. I know one is for the lockup but what about the other one? Also, the brakelight switch has 4 wires instead of two to activate the brake lights and open the circuit to the converter. I've not tried to wire this all into my 69 yet but one day will try it. And as far as how much decrease in rpm will result, I'll take all I can get. 350/350, 4:10 posi, low profile tires on the street. Maybe some day I'll intertain an overdrive but for now I'll run this combo. Merry Christmas all, Boog

[Longhorn Man]

On the switch, i can't speak for the '73 and up crowd, but on the '72 and down, you can get a brake light switch for a truck with cruise control. That will give you the terminals on the switch that you can use to disengage the lock up. However, it would be engaged as soon as you let off the brakes too, so it is only 1/2 the solution.

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The hot rod;
a'69 G.M.C. Short/Fleet. 350 W/a heluva cam and nice stance. Trying to clean up the left over damage from the Dope-Smokin-Old-Man. See it at http://geocities.com/andys_69_gmc/

I've been dubbed the Longhorn Freak/Fanatic/Expert, I just hope I can live up to it. Check out my Longhorn site at http://geocities.com/MotorCity/Flats/8752/

Need to pick up the one ton Longhorn with a 350/350 here soon, thanks every one!

If you need a pic posted, e-mail me at longhornmail@yahoo.com

[RodC]

I have this switch now, It is used to break the circuit and deactivete the interlocking relay.

BTW FYI
Here is what I have learned so far:

Sumit racing has a cool device to connect to you speedo so you can adjust what speed it locks up. This one is for a mechnical Speedo, Go to B&Ms web site for a digital speedo: http://store.summitracing.com/partde...188&part=12425

THIS Will answer questions about what is on the actual truck:
http://forums.chevytalk.com/forums/F...ML/002225.html
http://forums.chevytalk.com/forums/F...ML/002103.html
http://forums.chevytalk.com/forums/F...ML/002128.html

Good article on wiring a TCC for a TH700R4 should be similar for TH350C http://home.twcny.rr.com/mcss/drivetrain.html

I have more, the news groups are full of stuff about this just go to google.com and search the groups for TH350C, TCC and that sorta stuff