kickdown cable making problem

[LAVA]

I bought a 40 Plymouth project car with a 340 and 727 trans. Got the car driving and took it for a 1 mile ride. The trans worked fine. As I finished the car I put a Lokar kickdown cable on it. Here's the problem; Without the cable the trans works fine. With the cable it won't shift to 3rd gear. Kickdown works fine from 2nd to first. I've followed the 1to1 cable placement between the carb and linkage arm. I've adjusted it using the gas pedal floored instead of WOT at the carb. I changed fluid and filter. .........I saw someone on this forum recommend a small return spring on the arm and adjust the cable slightly to change shift points. I'm giving that a try next. Does anyone else have an idea I can try? I just want to try every suggestion on a day I can dedicate to this

 

[Plymouth 65]

I use the WOT method to adjust my cable. I'll typically leave it slightly loose at closed throttle/idle. Any pic of the 40 Plymouth? 65'

 

[oldkimmer]

I bought a 40 Plymouth project car with a 340 and 727 trans. Got the car driving and took it for a 1 mile ride. The trans worked fine. As I finished the car I put a Lokar kickdown cable on it. Here's the problem; Without the cable the trans works fine. With the cable it won't shift to 3rd gear. Kickdown works fine from 2nd to first. I've followed the 1to1 cable placement between the carb and linkage arm. I've adjusted it using the gas pedal floored instead of WOT at the carb. I changed fluid and filter. .........I saw someone on this forum recommend a small return spring on the arm and adjust the cable slightly to change shift points. I'm giving that a try next. Does anyone else have an idea I can try? I just want to try every suggestion on a day I can dedicate to this

@TrailBeast

 

[12many]

the gas pedal floored instead of WOT

I’ve seen this quote posted before in the past. Someone needs to explain exactly how there would be any difference between operating the throttle to WOT by hand at the carb vs. “flooring it” at the pedal. The throttle is closed regardless, and when you floor it via pedal it should be at WOT. No different than operating the throttle by hand as you’re bent over the fender! These Lokar trans kickdown cables are pulled at the carb as the throttle is opened.

 

[oldkimmer]

Does it have a factory carb with factory Chrysler linkage on it? If aftermarket carb does it have the Chrysler adapter? Without the factory type carb or the adaptor the ratio is wrong between the carb and the tranny. Kim

 

[RustyRatRod]

Well, lets get the totally incorrect assumption that the transmission "works fine" without the kickdown installed. It does not. The Torqueflite transmission MUST utilize some form of throttle pressure control, be it with solid linkage or a cable. Without that, the transmission will burn up 3rd gear first, followed by 2nd and finally first. The throttle pressure must increase in order to hold the clutches together as more power is applied. Unless you use a manual valve body, the kickdown linkage or cable MUST be used.

 

[toolmanmike]

I’ve seen this quote posted before in the past. Someone needs to explain exactly how there would be any difference between operating the throttle to WOT by hand at the carb vs. “flooring it” at the pedal. The throttle is closed regardless, and when you floor it via pedal it should be at WOT. No different than operating the throttle by hand as you’re bent over the fender! These Lokar trans kickdown cables are pulled at the carb as the throttle is opened.

"Gas pedal to the floor" may not make the carb to go "wide open".

 

[12many]

Well

"Gas pedal to the floor" may not make the carb to go "wide open".

Well that needs to be fixed first. Cut out carpet backing/insulation, adjust the throttle cable, etc. Easy as can be. Been there done that many times. Who drives around with a throttle where the pedal doesn’t achieve WOT? That’s problem number one. Number two is getting the lockdown cable adjusted. It doesn’t matter if your sitting in the car flooring it by foot or opening the throttle by hand. Right? Exactly

 

[toolmanmike]

Well

Well that needs to be fixed first. Cut out carpet backing/insulation, adjust the throttle cable, etc. Easy as can be. Been there done that many times. Who drives around with a throttle where the pedal doesn’t achieve WOT? That’s problem number one. Number two is getting the lockdown cable adjusted. It doesn’t matter if your sitting in the car flooring it by foot or opening the throttle by hand. Right? Exactly

Exactly. Hey, it's a 40 Plymouth with a 340 in it. The original pedal/throttle was a rod through the firewall to a flathead 6. Who knows what combination is in there now.

 

[TrailBeast]

I bought a 40 Plymouth project car with a 340 and 727 trans. Got the car driving and took it for a 1 mile ride. The trans worked fine. As I finished the car I put a Lokar kickdown cable on it. Here's the problem; Without the cable the trans works fine. With the cable it won't shift to 3rd gear. Kickdown works fine from 2nd to first. I've followed the 1to1 cable placement between the carb and linkage arm. I've adjusted it using the gas pedal floored instead of WOT at the carb. I changed fluid and filter. .........I saw someone on this forum recommend a small return spring on the arm and adjust the cable slightly to change shift points. I'm giving that a try next. Does anyone else have an idea I can try? I just want to try every suggestion on a day I can dedicate to this
[/QUOTE]


[/QUOTE]
First you need a light spring that pulls the lever on the trans fully forward at zero throttle opening.
Your lever doesn’t do that on it’s own.
Not having the spring on the lever holds your throttle pressure up making it seem like everything is fine, but it also makes the trans think you don’t need 3rd gear yet.

From the lever on the trans to the front cooler like works good.

Put the spring on it and I’ll bet it solves the problem.

First you need a light spring that pulls the lever on the trans fully forward at zero throttle opening.
Your lever doesn’t do that on it’s own.
Not having the spring on the lever holds your throttle pressure up making it seem like everything is fine, but it also makes the trans think you don’t need 3rd gear yet.

From the lever on the trans to the front cooler line works good.

Put the spring on it and I’ll bet it solves the problem.

 

[Ricks70Duster340]

First you need a light spring that pulls the lever on the trans fully forward at zero throttle opening.
Your lever doesn’t do that on it’s own.
Not having the spring on the lever holds your throttle pressure up making it seem like everything is fine, but it also makes the trans think you don’t need 3rd gear yet.

From the lever on the trans to the front cooler line works good.

Put the spring on it and I’ll bet it solves the problem.

Exactly. I had to put a spring on mine to fully retract the lever. The throttle return springs on the carb were not enough to make that happen.

 

[LAVA]

Thanks for all of the replies. First, I wasn't implying that the transmission was fine without a kickdown cable, I know I need a kickdown cable. I was only stating that the shift points were in their proper spots after sitting 20 years. Second, using the pedal instead of the carb for full throttle was a post Id seen already so I wanted to let everyone know I tried that already. I have a Lokar throttle cable and lokar kickdown assembly..... Now here's how I fixed it. The instructions say to go full throttle and then pull the kickdown cable to move the lever to full pressure and tighten it at full throttle. Doing that was making the cable housing flex and making the adjustment too tight. So I changed the way I adjusted it. I wired the kickdown arm back at full pressure and then went to the carb for WOT and then pulled the cable and tightened it. Now my shift points are spot on. Kickdown is good but it doesn't always work. I think I'll really have to stomp it down. IMO the kickdown cable isn't as precise as it should be. It's braided stainless steel and IMO it shouldn't be flexing under cable pressure. Or, maybe my trans is worn, after all, it's 50 years old and I have no idea where it came from. Thanks for all the input

 

[toolmanmike]

Nice old coupe. Now that you have the cable adjusted close you can fine tune it to get the kickdown to work properly. It sounds like the cable adjustment is too tight. Loosen it up a smidge until you get what you need.

 

[Plymouth 65]

Nice Coupe, I'm currently working on mine. Thanks for the pictures! 65'

 

[12many]

Doing that was making the cable housing flex and making the adjustment too tight.

My setup is 100% improvised. I use a Lokar throttle cable along with my original throttle rod and bell crank on my van. My pedal has a rod that passes through the floor to a bell crank, then a long rod that runs back alongside the frame rail (with guides)
The Lokar cable is secured to a mount, the inner wire is connected to the rod end and the cable loops up on the backside of the engine up to a bracket on the intake that it mounts to. The inner wire then connects to the carb.

Originally the cable housing would flex when opening the throttle, be all squiggly (for lack of a better term) and I couldn’t get to full throttle, and it was too stiff.

What I did was use a length of brake line and bent it to the radius I needed from where the cable connected to the throttle rod below at the frame with a section of hose (to accommodate engine movement) up to the cable mount on the engine. Then I ran the cable housing through the brake line and hooked everything up.

Short story long... for your kickdown you might try using some brake line and bend it in a manner so as to replicate how the cable situates when hooked up. Feed the cable into the brake line, then hook it all up. How much brake line you would need depends. Might just need it for the big radius where it loops around at the back of the trans, maybe longer. Perhaps the whole length. Would be easy to fabricate regardless. That WILL prevent any flexing. 100% guaranteed

I have a full manual valve body so I don’t use a kick down (I did on my van originally but I suffered the same issue as you mention for some reason) but if I did again I would look into this:

BPE TorqueFlite Kickdown Cable Kit - Bouchillon Performance Engineering

 

[LAVA]

My setup is 100% improvised. I use a Lokar throttle cable along with my original throttle rod and bell crank on my van. My pedal has a rod that passes through the floor to a bell crank, then a long rod that runs back alongside the frame rail (with guides)
The Lokar cable is secured to a mount, the inner wire is connected to the rod end and the cable loops up on the backside of the engine up to a bracket on the intake that it mounts to. The inner wire then connects to the carb.

Originally the cable housing would flex when opening the throttle, be all squiggly (for lack of a better term) and I couldn’t get to full throttle, and it was too stiff.

What I did was use a length of brake line and bent it to the radius I needed from where the cable connected to the throttle rod below at the frame with a section of hose (to accommodate engine movement) up to the cable mount on the engine. Then I ran the cable housing through the brake line and hooked everything up.

Short story long... for your kickdown you might try using some brake line and bend it in a manner so as to replicate how the cable situates when hooked up. Feed the cable into the brake line, then hook it all up. How much brake line you would need depends. Might just need it for the big radius where it loops around at the back of the trans, maybe longer. Perhaps the whole length. Would be easy to fabricate regardless. That WILL prevent any flexing. 100% guaranteed

I have a full manual valve body so I don’t use a kick down (I did on my van originally but I suffered the same issue as you mention for some reason) but if I did again I would look into this:

BPE TorqueFlite Kickdown Cable Kit - Bouchillon Performance Engineering

Thank You 12many, excellent idea!