A518 kickdown adjustment

[rcannon440]

How do you know if you have the kickdown cable/linkage adjusted properly on your 727/518 transmission?

[John_Kunkel]

With the carb at idle the trans lever should be full forward, with the carb at WOT the trans lever should be NEAR full rearward.

[rcannon440]

That's where I have it set to now, the problem is with it like this the car shifts gears way to soon and it never down shifts when I go to WOT. That's why I thought I must have it set wrong. Also does the lever on the transmission need a return spring?

[John_Kunkel]

Do you have a cable or linkage? If you have linkage is the carb stock or aftermarket? If aftermarket do you have the correct Mopar throttle lever extension?

If you have a cable and it's a Lokar 

[rcannon440]

I have a Lokar after market cable kit hooked up to an Edelbrock carb.

[cdr]

i used the cable from the dodge truck that my 518 came from.

[flyinlow]

My 518 had a spring that pulled the throttle position or kick down lever toward the idle position. I still use it even though I am using a modified '73 kick down rod to control mine.

Sounds like you need the  pin on the carb to start moving your cable earlier. At wide open throttle shifts should occur at about 5000+ rpm. Part throttle down shift should occur normally.
If I remember right the stock setup on a 518 uses a cable that makes a 180* turn behind the throttle position lever and pulls on it. What ever you use ,the arcs and travel of the carb pin and the throttle position lever have to co-inside.
Adjustments on mine as small 1/8 " at the carb pin will make it not quite right. Too little throttle position gives you early shifts, no kick down and flaring in the 2-3 shift. Too much gives you late shifts at part throttle and of course the carb won't open fully.

Safety issue: make sure the linkage has a slot or  some device to let the carb return to idle in case the throttle position linkage jams . 

[John_Kunkel]

I have a Lokar after market cable kit hooked up to an Edelbrock carb.

Even though the Lokar might be marketed as being for a Mopar, it's actually more of a generic setup because there is such a wide variety of transmission levers and carb levers.

You need to measure the full travel of the carb lever where the cable attaches and then measure the full travel of the transmission lever where the cable attaches; it usually won't be the same so you need to drill a new hole in the transmission lever so that the full travel of both levers is the same.

There should also be a spring pulling the transmission lever forward.

Also, be sure that WOT under the hood is the same as WOT at the pedal...misadjusted throttle linkage will prevent the carb from going wide open when the pedal is matted and that, in turn, will prevent the trans lever from going back enough to provide kickdown.

[rcannon440]

Thanks for the reply's. I found that I was missing the return spring for the transmission lever and I also adjusted the cable because it had to much play in it. This has helped a lot and the car runs much better, although I have noticed that the transmission will not kick down into passing gear unless I have the overdrive turned off by a switch.