Hey tranny gurus - The 1947 - Present Chevrolet & GMC Truck Message Board Network

chevyguy_72 · 08-23-2005, 07:48 PM

I have a TH400. Have had it for a while. What are the electrical connections on the driver side? I have asked around town and recieved about 3 different answers. One told me it was electronic kickdown. One said it was to hook up reverse lights. and one said it was to control a lock up torque converter. Which one is right? If it is going to be something beneficial i want to hook it up. If not i am not too worried about it.
Thanks

Robert1970C20rstbukt · 08-23-2005, 08:01 PM

That terminal is for the electric kickdown, there was either a switch on the carb(67-70) or a switch on the accelerator pedal(71-72) that downshifted the transmission to the passing gear.(2nd) I don't think it has to be hooked up though.

JimKshortstep4x4 · 08-23-2005, 08:02 PM

It is for the electric kickdown detent switch. There should be a switch on your accelerator, inside, (71, 72's).

Jim

cowboy33713 · 08-23-2005, 08:04 PM

Howdy:
It is for the electric "passing gear" kickdown. The TH 350 used a cable activated kickdown. The 400 has an electric kickdown. On 67-69(?)trucks the switch for this was mounted near the carburator, where it would be pressed by the throttle arm when near full throttle (like when you wanted to pass someone now!). Later, it was mounted on the bracket for the accelerator pedal, under the dashboard (the usual set up after GM was using cable throttles in place of old fashioned rod linkage). There are a couple of suppliers who make a one size fits most type replacement for those of us in need of a way to make the T400 downshift using the throttle as GM had intended; I will likely buy the one that Lokar makes - almost too nice to hide under a truck.
cowboy33713

Longhorn Man · 08-23-2005, 09:02 PM

The TH400 will actually go from 3rd to 2nd with the wire unplugged... it is for when you floor it and it needs to go to first gear...that's what it is for.

chevyguy_72 · 08-23-2005, 10:09 PM

does anyone have a picture of what the oem piece looks like?
Thanks

08-23-2005, 07:48 PM	#1
chevyguy_72 Vintage Evil Join Date: Aug 2005 Location: Broomfield, CO Posts: 956	Hey tranny gurus I have a TH400. Have had it for a while. What are the electrical connections on the driver side? I have asked around town and recieved about 3 different answers. One told me it was electronic kickdown. One said it was to hook up reverse lights. and one said it was to control a lock up torque converter. Which one is right? If it is going to be something beneficial i want to hook it up. If not i am not too worried about it. Thanks __________________ Current Rides: Vintage Evil - 72 Chevy C10 (Always a work in progress) Vintage Evil Build Thread EvilK5 - 71 K5 Blazer Evil Twin - 2006 Suzuki M109R EvilDmax- 2018 GMC 2500 Denali Duramax

08-23-2005, 08:01 PM	#2
Robert1970C20rstbukt Registered User Join Date: Jun 2004 Location: Beeville, Texas Posts: 1,943	That terminal is for the electric kickdown, there was either a switch on the carb(67-70) or a switch on the accelerator pedal(71-72) that downshifted the transmission to the passing gear.(2nd) I don't think it has to be hooked up though. __________________ RJD 1984 Chevrolet C30 welding truck 454/SM465 1977 GMC C15 pickup 350/TH350 1970 Chevrolet C20 pickup 350/TH400 1970 Chevrolet K20 Suburban 454/TH350 1969 GMC 8500 478M V6/5 spd winch truck

08-23-2005, 10:09 PM	#6
chevyguy_72 Vintage Evil Join Date: Aug 2005 Location: Broomfield, CO Posts: 956	does anyone have a picture of what the oem piece looks like? Thanks __________________ Current Rides: Vintage Evil - 72 Chevy C10 (Always a work in progress) Vintage Evil Build Thread EvilK5 - 71 K5 Blazer Evil Twin - 2006 Suzuki M109R EvilDmax- 2018 GMC 2500 Denali Duramax

08-23-2005, 08:02 PM	#3
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	It is for the electric kickdown detent switch. There should be a switch on your accelerator, inside, (71, 72's). Jim

08-23-2005, 08:04 PM	#4
cowboy33713 Senior Member Join Date: Apr 2005 Location: metro Phoenix, AZ Posts: 241	Howdy: It is for the electric "passing gear" kickdown. The TH 350 used a cable activated kickdown. The 400 has an electric kickdown. On 67-69(?)trucks the switch for this was mounted near the carburator, where it would be pressed by the throttle arm when near full throttle (like when you wanted to pass someone now!). Later, it was mounted on the bracket for the accelerator pedal, under the dashboard (the usual set up after GM was using cable throttles in place of old fashioned rod linkage). There are a couple of suppliers who make a one size fits most type replacement for those of us in need of a way to make the T400 downshift using the throttle as GM had intended; I will likely buy the one that Lokar makes - almost too nice to hide under a truck. cowboy33713

08-23-2005, 09:02 PM	#5
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	The TH400 will actually go from 3rd to 2nd with the wire unplugged... it is for when you floor it and it needs to go to first gear...that's what it is for.



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.