TH 400 KIck down? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

muscletruck · 08-26-2002, 02:45 AM

hey all.....i want to have my TH 400 have the "kick down" option on it so what all do i need to buy or get for this to happen..i wanna be able to floor it and feel that tranny drop back to second than chirp into third...GONNA HAVE TO GET A BIGGER POWERPLANT THOUGH

JimKshortstep4x4 · 08-26-2002, 07:34 AM

You will need the kickdown switch, for mounting on your carburetor, bracket for a Holly or Q-Jet, (to fit the carb that you have on your engine), tab to mount on the throttle, and the wiring. I would suggest that you post on the parts wanted board
for the setup. The described setup is for a 69 which it appears that you have. 71-72's are different.

Jim

gabet40 · 08-26-2002, 10:48 AM

i just changed from a 400 to a 700r4 in my truck and still have the kickdown switch and maybe the oakey rigged tab that i attached to my throttle plate to activate it. pay shippin and its yours. email me if your interested

**COBALT** · 08-26-2002, 02:32 PM

I just went through this process trying to find a kick-down switch for my TH400 for a 2bbl carb. Luckily its easier to find for a 4bbl. Here's a picture of what you're looking for for different carbs.

Jwill41 · 08-26-2002, 02:49 PM

I have a th400 in my 67 with no kickdown switch. It only has a vacume hose going to the manifold. It seems to me that it kicks down like it should. How can this be?

muscletruck · 08-26-2002, 02:59 PM

Gabet....do you know if it will fit my carb, holley 650 (4175)(POS)...its in the rebuild prcess so hopefully no P.O.S.....anywho..do you know if it will?......thanks for the offer!

murfslaw · 08-26-2002, 03:41 PM

PAW carries a Lokar switch and you can still buy the bracket from your chevy dealer.

**COBALT** · 08-26-2002, 03:57 PM

Jwill41: Yes, it will still kick down but pretty rough, and you'll have to hammer the gas to do it. The 400 regulates shifts based on rpm, fluid pressure AND whether or not the detent circuit is activated (current is getting to the detent soleniod inside the pan). You're missing the third element which makes everything much smoother.

Mine would kickdown, but it always felt like I was jamming the damn thing into 2nd. After I installed that detent switch on the carb (thanks to breeh) it would pause for a fraction of a second, then smoothly slide into 2nd, which is what its supposed to do with stock valve body. And that's without having to hammer the gas.

Either way its good to have one.

**COBALT** · 08-26-2002, 04:01 PM

Oh yeah, and another thing. PICKMUP suggested Lokar when I was trying to find an aftermarket switch. They look like they have a damn good setup for 4bbl-to-400 detent switch. The switch actually bolts to the transmission, and a cable activates the switch from a bracket on the carb. Nice and clean without the switch on the carb, but it looks like $$$ because it's all stainless.

ChevLoRay · 08-26-2002, 05:05 PM

The Lokar switch actually mounts at the transmission, with the cable from the carb acting as the actuator. The cable has to be cut to length.

As for operating (kicking down) without any actuator, it is being done by vacuum, or actually a lack of it. I had my valve body modified (no shift kit) and the modulator valve was changed to a little ole bitty one. My tranny will kick down, but it is due to a lack of vacuum. I have the Lokar switch, but haven't installed it yet. Heck, I've only had the switch for about 2 years....what do you expect? I have kids and grandkids and no job and, aw what difference does it make? I'll put it in when I get good and ready and it cools off and it ain't raining and I'm not hungry and yada, yada, yada.

The Lokar switch is a really clean item to have, if you can't get your hands on the original type or your carb has been changed and you can't use the original. Mine was removed when someone put on an Edelbrock 1405. I put an Edelbrock 1901. I may try to find an old switch and bracket.

gabet40 · 08-27-2002, 04:27 AM

well my switch is for a four barrel but i had it on a quadrajet, and lookin at the photo of your carb on the holley website, they dont look anything alike. but the mounting has to be pretty similar right? i think itll fit.
like i said, you pay shipping and its yours, id be a lot happier with it there possibly puttin some good use to it than sittin in a box full of parts from my old 350 in the shed.

speakin of good use, funny story to my kickdown switch, i didnt even know i had one until my electrical shop accidently connected it to my parking lights. so anytime at night, i would have to bring her up to about 3800 rpms to shift and didnt know what was goin on! once i straightened it out, boy thats a nice switch

08-26-2002, 02:45 AM	#1
muscletruck Registered User Join Date: Jan 2002 Location: anahiem,ca,usa Posts: 201	TH 400 KIck down? hey all.....i want to have my TH 400 have the "kick down" option on it so what all do i need to buy or get for this to happen..i wanna be able to floor it and feel that tranny drop back to second than chirp into third...GONNA HAVE TO GET A BIGGER POWERPLANT THOUGH __________________ i think i found me truck! 78 Crew Cab Dually 454/TH400, Dual Flows, Edelbrock Intake, Cam, Lifters, Billet Grill, K&N Airfilter, Grant Steering Wheel, A/C, soon to be power windows and locks, lots of plans for this... ....gas prices go down please

08-26-2002, 10:48 AM	#3
gabet40 Registered User Join Date: Dec 1999 Location: Modesto, CA Posts: 565	i just changed from a 400 to a 700r4 in my truck and still have the kickdown switch and maybe the oakey rigged tab that i attached to my throttle plate to activate it. pay shippin and its yours. email me if your interested __________________ Current owner of 2016 2500 Silverado Midnight Edition. Former owner of: 69 1/2 ton, change from long/fleet to short/fleet, shaved door handles, shaved tailgate, 4/6 drop, power windows, 700r4 72 blazer, 350 with Holley Commander 950 DFI, crane energizer cam, 350 tranny, dual sanderson blockhuggers/magnaflow exhaust

08-26-2002, 02:32 PM	#4
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	I just went through this process trying to find a kick-down switch for my TH400 for a 2bbl carb. Luckily its easier to find for a 4bbl. Here's a picture of what you're looking for for different carbs. Attached Images __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

08-26-2002, 02:49 PM	#5
Jwill41 Registered User Join Date: Aug 2002 Location: Farmers Branch, Tx Posts: 1,009	I have a th400 in my 67 with no kickdown switch. It only has a vacume hose going to the manifold. It seems to me that it kicks down like it should. How can this be? __________________ http://www.picturetrail.com/jwill41 67 1/2 ton GMC short step side 68 1/2 ton Chevy long fleet side 72 1/2 ton Chevy Suburban 99 1/2 ton Chevy Suburban founder (and only member) of the primer/clearcoat club

08-26-2002, 02:59 PM	#6
muscletruck Registered User Join Date: Jan 2002 Location: anahiem,ca,usa Posts: 201	sweet Gabet....do you know if it will fit my carb, holley 650 (4175)(POS)...its in the rebuild prcess so hopefully no P.O.S.....anywho..do you know if it will?......thanks for the offer! __________________ i think i found me truck! 78 Crew Cab Dually 454/TH400, Dual Flows, Edelbrock Intake, Cam, Lifters, Billet Grill, K&N Airfilter, Grant Steering Wheel, A/C, soon to be power windows and locks, lots of plans for this... ....gas prices go down please

08-26-2002, 07:34 AM	#2
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	You will need the kickdown switch, for mounting on your carburetor, bracket for a Holly or Q-Jet, (to fit the carb that you have on your engine), tab to mount on the throttle, and the wiring. I would suggest that you post on the parts wanted board for the setup. The described setup is for a 69 which it appears that you have. 71-72's are different. Jim

08-26-2002, 03:41 PM	#7
murfslaw Registered User Join Date: Apr 2000 Location: Tarzana, CA Posts: 78	PAW carries a Lokar switch and you can still buy the bracket from your chevy dealer. __________________ 69 C10 lwb, 400 sb, Turbo 400,

08-26-2002, 03:57 PM	#8
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	Jwill41: Yes, it will still kick down but pretty rough, and you'll have to hammer the gas to do it. The 400 regulates shifts based on rpm, fluid pressure AND whether or not the detent circuit is activated (current is getting to the detent soleniod inside the pan). You're missing the third element which makes everything much smoother. Mine would kickdown, but it always felt like I was jamming the damn thing into 2nd. After I installed that detent switch on the carb (thanks to breeh) it would pause for a fraction of a second, then smoothly slide into 2nd, which is what its supposed to do with stock valve body. And that's without having to hammer the gas. Either way its good to have one. __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

08-26-2002, 04:01 PM	#9
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	Oh yeah, and another thing. PICKMUP suggested Lokar when I was trying to find an aftermarket switch. They look like they have a damn good setup for 4bbl-to-400 detent switch. The switch actually bolts to the transmission, and a cable activates the switch from a bracket on the carb. Nice and clean without the switch on the carb, but it looks like $$$ because it's all stainless. __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA. Last edited by COBALT; 08-26-2002 at 05:08 PM.

08-26-2002, 05:05 PM	#10
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	The Lokar switch actually mounts at the transmission, with the cable from the carb acting as the actuator. The cable has to be cut to length. As for operating (kicking down) without any actuator, it is being done by vacuum, or actually a lack of it. I had my valve body modified (no shift kit) and the modulator valve was changed to a little ole bitty one. My tranny will kick down, but it is due to a lack of vacuum. I have the Lokar switch, but haven't installed it yet. Heck, I've only had the switch for about 2 years....what do you expect? I have kids and grandkids and no job and, aw what difference does it make? I'll put it in when I get good and ready and it cools off and it ain't raining and I'm not hungry and yada, yada, yada. The Lokar switch is a really clean item to have, if you can't get your hands on the original type or your carb has been changed and you can't use the original. Mine was removed when someone put on an Edelbrock 1405. I put an Edelbrock 1901. I may try to find an old switch and bracket. __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.

08-27-2002, 04:27 AM	#11
gabet40 Registered User Join Date: Dec 1999 Location: Modesto, CA Posts: 565	well my switch is for a four barrel but i had it on a quadrajet, and lookin at the photo of your carb on the holley website, they dont look anything alike. but the mounting has to be pretty similar right? i think itll fit. like i said, you pay shipping and its yours, id be a lot happier with it there possibly puttin some good use to it than sittin in a box full of parts from my old 350 in the shed. speakin of good use, funny story to my kickdown switch, i didnt even know i had one until my electrical shop accidently connected it to my parking lights. so anytime at night, i would have to bring her up to about 3800 rpms to shift and didnt know what was goin on! once i straightened it out, boy thats a nice switch __________________ Current owner of 2016 2500 Silverado Midnight Edition. Former owner of: 69 1/2 ton, change from long/fleet to short/fleet, shaved door handles, shaved tailgate, 4/6 drop, power windows, 700r4 72 blazer, 350 with Holley Commander 950 DFI, crane energizer cam, 350 tranny, dual sanderson blockhuggers/magnaflow exhaust



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.