Kickdown

[JR1]

Maybe one of you guys can answer this question, my truck has th400 behind a 350, h052 in rear, when I drive easy it shifts at about 9 or 10mph and then at about 25 mph, if i get on it, its 16mph and 35mph, but if im above 30 mph and its already in 3rd i can floor it and it wont downshift, it just bogs until it goes into second at around 20 to 25, the camper does bog it on hills, is this a governor or something to avoid high downshifts...i had a mechanic check the vacuum and downshift mechanism on the tranny and he said it was good, can someone post a pic of the carburetor part of the kickdown, I've heard a th400 is a vacuum kickdown no cable but then ive read stuff about a carborator part of the system, this has a new carb so maybe part of the mechanism i missing

I at first put this on the wrong thread so I'm re poring here, thanks

[LockDoc]

Originally Posted by JR1

Maybe one of you guys can answer this question, my truck has th400 behind a 350, h052 in rear, when I drive easy it shifts at about 9 or 10mph and then at about 25 mph, if i get on it, its 16mph and 35mph, but if im above 30 mph and its already in 3rd i can floor it and it wont downshift, it just bogs until it goes into second at around 20 to 25, the camper does bog it on hills, is this a governor or something to avoid high downshifts...i had a mechanic check the vacuum and downshift mechanism on the tranny and he said it was good, can someone post a pic of the carburetor part of the kickdown, I've heard a th400 is a vacuum kickdown no cable but then ive read stuff about a carborator part of the system, this has a new carb so maybe part of the mechanism i missing

I at first put this on the wrong thread so I'm re poring here, thanks

What year is your truck? Up to '70 the electric kickdown switch was on the carb. '71 up was on the accelerator pedal inside the truck....

LockDoc

[demian5]

Originally Posted by LockDoc

What year is your truck? Up to '70 the electric kickdown switch was on the carb. '71 up was on the accelerator pedal inside the truck....

LockDoc

Sometimes you have to wrap and zip-tie a couple pieces of fuel line on the throttle pedal linkage and kick down switch to get it to make contact so it does its job.

[LockDoc]

Originally Posted by demian5

Sometimes you have to wrap and zip-tie a couple pieces of fuel line on the throttle pedal linkage and kick down switch to get it to make contact so it does its job.

I haven't looked at the one I have close. Isn't there an adjustment on it? I will have to look at mine tomorrow.

LockDoc

[JR1]

thanks guys, I am narrowing in on the problem from not having any clue to how these worked to having an idea of what to look for, so more pieces to the puzzle, the previous owner put a holley carb on it, now that I have been researching and seeing pics and your info I don't even think this has the switch anymore, ill check tonight..... the parts on the trans are all working, they were checked by a mechanic, however, im guessing they are not hooked up to the twelve volt switch, I should know tonight and then ask where the wires go.... hopefully

[FirstOwner69]

From your picture, it appears you have a '69 or '70. I think both years still had the carb mounted kickdown as shown below in the 1st picture. I bought a Lokar kickdown switch for the Holley on my crate engine to replace the stock setup. The 2nd picture shows the Lokar switch mounted to the left side of the transmission. The 3rd picture shows the linkage to the Holley. I made a simple bracket from angle aluminum and attached it to the rear carb stud.

[JR1]

Awesome....I'm start in to get it....gonna fix it this weekend

[FirstOwner69]

Here's a link to the lowest price Lokar kit on eBay.


https://www.ebay.com/itm/Lokar-KD-24...9Y3tkU&vxp=mtr

[JR1]

well I checked last night and then worked this morning, sure enough the PO removed the kickdown switch from the manifold when he put the new manifold and carburetor on, I found the tranny wire still connected and tied off and I think I actually found the 12 wire tied off, so now just to add the switch, I see this morning the last info was lokar, I happened to run into info on the b and m kit last night with a little tutorial so I ordered that, seems easy to install...I hope I didn't get the wrong one but it seems real good on the tutorial..im super stoked cause that is the only thing I didn't like about this truck. im just getting used to these carbureted things, I had carburetors when I was a kid but never could afford an automatic so never even knew about kickdown, with this truck I felt the 2nd two barrels opening and kinda thought that was the kickdown and the truck was just a dawg, but someone suggested downshifting manually at speed and flooring it and sure enough that is what I was lookin for, so now with this kit I should be back in action and not need a new motor for awhile.....steep learning curve on auto work but you guys are really helping, thank you.

[demian5]

Originally Posted by JR1

well I checked last night and then worked this morning, sure enough the PO removed the kickdown switch from the manifold when he put the new manifold and carburetor on, I found the tranny wire still connected and tied off and I think I actually found the 12 wire tied off, so now just to add the switch

Nothing on the pedal inside of the cab? post a picture.

Here is more info from the search feature:

http://67-72chevytrucks.com/vboard/s...d.php?t=660593

http://67-72chevytrucks.com/vboard/s...d.php?t=169473

http://67-72chevytrucks.com/vboard/s...d.php?t=716980

http://67-72chevytrucks.com/vboard/s...d.php?t=358778

[demian5]

Originally Posted by LockDoc

I haven't looked at the one I have close. Isn't there an adjustment on it? I will have to look at mine tomorrow.

LockDoc

After being "floored" for 50 years, any adjustment is moot. Every 400 I've had with the kickdown switch in the cab, I had to fill the gap with hose - usually a piece on the switch and a piece on the pedal arm. I imagine the years of abuse and lead foots actually straightens the bend in the pedal linkage, flattening it out.

[JR1]

no switch on the pedal or a bracket or any sign of anything ever being there, this is a 69 and some have said they moved to the pedal in 70 or 71

[demian5]

Originally Posted by JR1

no switch on the pedal or a bracket or any sign of anything ever being there, this is a 69 and some have said they moved to the pedal in 70 or 71

It appears the winning solution is a squarebody pedal assembly. Either way, i would put a switch on the pedal, then no mater what carb or BS goes on in the engine compartment, it will work and be safe from the elements.

[JR1]

that does seem the easiest, probly why they moved it there in 70, but I already bought this kit and am gonna give it a try, thank you though, if it doesn't work, back to the peddle!

[JR1]

Made a nice switch mount, hours with install, had to do trans service to get new selinoid in, shorted some wires and melted then all the way into fuse panel, lotta smoke, found during that fix the wires were old and bad, ignition and electric choke wires, broke a bolt in tranny pan, carburator fire during switch cable adjustment, musta knocked an alternator wire off climbing around in there so i got stranded 3rd day testing it to and from work......but, IT RUNS LIKE A NEW TRUCK, so happy , 20 hour job and worth every second......steep learning curve here for sure but you guys are awesome, so fun!

[dmjlambert]

Wow, now that is some news. Let's see pictures please. With all the stuff that went wrong, that would have been 150 hour job for me. :-)

[JR1]

Even without the kickdown the truck runs so much better, plugs, wires,cap rotor, fuel filter, coil, timing adjust, carb adjust, it all added up i guess, but to my surprise (life does surprise me a lot though) the new wire to the ignition and choke made the biggest difference, added benefit while moving brake assist vac line i noticed it loose, brakes are much better........pics coming in 45 min, STILL TRYING TO EXPLAIN TO MY WIFE WHERE I'VE BEEN EVERY NIGHT!

[JR1]

Here's the pic of the mount I made for the b and m kickdown switch with top part to hold up vac line.....man she is running good!

[weq92f]

Flip fa ya...

-klb

[JR1]

I couldn't figure out how to do that, thanks