wiring the lockup, T350C? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**Boog** · 07-06-2006, 09:21 PM

from the pole:what tranny do you have
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Well it looks like the T350 is the most used in our trucks. Close count with the others though. Only 2 of us have a T350C. While I don't know anything about these trannys I hope it is as good as a regular 350. Mine needs to be built and I have to find out how to wire the clutch converter up proper. I assume all I'll need is a fused power to a brake pedal mounted switch then down to the tranny plug. Anyone have the schematic necessary to make it work? Aren't there about 4 pins in the trans connector? I know I can also install a toggle switch for it but would prefer it to be automatic.
I also have a long tail T350 from a 70 something truck. Any benefit to using it instead?
My mind is made up to stay with the 350 trans. Plain and simple for this one, a carb and NO OD. Call it retro if you like.

Longhorn Man · 07-06-2006, 09:43 PM

I have no real info on the Th350C, just what I've been told by a few ppl;
i've been told it is a weaker version. That is all the info i have on that. Acurate or not... no idea.
As for the electronics, you can go 2 ways. The stock way there was a switch that was \run off the engine vacume. Once in 3rd gear, and high vacume conditions (no longer accelerating) it would lock up the converter. While I have never heard of this part, I would say it needs a switch on the brake pedal...or to run off the power coming going to the brake lights, otherwise, it would stall in a panic stop situation, and that would also damage the internals of the converter if you slammed your brakes on a lot without it dsengaging. That is the way the TH350 was done up originally.
However, there is an electronic solution which is most likely more dependable. B&M, and other trans companies, have a small electronic box that'll control the lock up. You can set the speed that it kicks in too, which is an added bonus.
Which ever route you go, running a lock up converter, with no lock up function (as in disabled or never hooked up) will shorten the life of both the converter, and the tranny,. We aren't talking like a mis adjusted 700, but, it will shorten it's life.

07-06-2006, 09:21 PM	#1
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 13,118	wiring the lockup, T350C? from the pole:what tranny do you have -------------------------------------------------------------------------------- Well it looks like the T350 is the most used in our trucks. Close count with the others though. Only 2 of us have a T350C. While I don't know anything about these trannys I hope it is as good as a regular 350. Mine needs to be built and I have to find out how to wire the clutch converter up proper. I assume all I'll need is a fused power to a brake pedal mounted switch then down to the tranny plug. Anyone have the schematic necessary to make it work? Aren't there about 4 pins in the trans connector? I know I can also install a toggle switch for it but would prefer it to be automatic. I also have a long tail T350 from a 70 something truck. Any benefit to using it instead? My mind is made up to stay with the 350 trans. Plain and simple for this one, a carb and NO OD. Call it retro if you like. __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross Last edited by Boog; 07-06-2006 at 09:24 PM.

07-06-2006, 09:43 PM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: wiring the lockup, T350C? I have no real info on the Th350C, just what I've been told by a few ppl; i've been told it is a weaker version. That is all the info i have on that. Acurate or not... no idea. As for the electronics, you can go 2 ways. The stock way there was a switch that was \run off the engine vacume. Once in 3rd gear, and high vacume conditions (no longer accelerating) it would lock up the converter. While I have never heard of this part, I would say it needs a switch on the brake pedal...or to run off the power coming going to the brake lights, otherwise, it would stall in a panic stop situation, and that would also damage the internals of the converter if you slammed your brakes on a lot without it dsengaging. That is the way the TH350 was done up originally. However, there is an electronic solution which is most likely more dependable. B&M, and other trans companies, have a small electronic box that'll control the lock up. You can set the speed that it kicks in too, which is an added bonus. Which ever route you go, running a lock up converter, with no lock up function (as in disabled or never hooked up) will shorten the life of both the converter, and the tranny,. We aren't talking like a mis adjusted 700, but, it will shorten it's life.



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