Vannin' Home Forums Dodge How To (Dodge) How do you adjust the kickdown (79 318ci)

the rod was all the way at the end when I started, and I had no kick down.

how much play should that arm have?

this is where it is now, which is about where I started, maybe am 1/8th of an inch further out.

Define "play."

With the kick down linkage from the carb disconnected, the kick down arm on the transmission should be able to move roughly 120 degrees from the front of the vehicle towards the back of the vehicle. With the kick down linkage disconnected, the kickdown arm should automatically travel towards the front of the vehicle until it contacts the internal stop. With the kick down linkage connected and the throttle held all the way open (and, therefore, the kick down linkage pushed back) the kick down arm on the transmission should be held against its rearward internal stop.

The kick down arm should be solidly linked to the kick down linkage. There should be no play between the arm and the linkage. The spring on the linkage is just a pre-load spring and doesn't really do much in terms of the operation of the kick down.

The kick down linkage controls the internal line pressure in the transmission which, in turn, controls the shift points of the transmission. The kick down linkage also tells the transmission when to "kick down" from 2 to 1 or from 3 to 2. As you can see, the adjustment of the kick down linkage is critical to the proper functioning of a Mopar 904 or 727 transmission. Disconnecting the kick down or having it misadjusted will lead to poor transmission performance and early transmission failure.

The key points to remember are this- the arm on the transmission should move when the throttle on the carb moves, and at wide open throttle the arm on the transmission should be held as far towards the rear of the vehicle as possible.

Where you have it now is fine, so long as it was adjusted with the throttle all the way open.

I have it all the way at the end of the rod now, and have kickdown if I floor it and wait a moment, which is more than I had.

Are you making sure the throttle is all the way open when you are making the adjustment? It sounds like your transmission isn't working right. If your van has the original 1979 transmission, it should have a part throttle as well as a full throttle kick down. Part throttle kick down became standard in the very early 70s.

If I were you, if you have followed the instructions above detailing how to adjust the kick down arm, I would now do band adjustments on the trans and make sure you have the right amount of fluid in it. Use Dexron-VI fluid. Dextrin III is obsolete, as is ATF+4 (what I used to recommend). Dextron -VI is the best fluid for you to use in your transmission.

This all assumes that someone hasn't been in the transmission swapping valve body or modifying the valve body. That trans looks pretty grungy. My guess is that is hasn't been opened up and you need to adjust the bands at a minimum.

Astro, I don't believe the kickdown adjustment on a 727 transmission is to be made with the accelerator pedal depressed at all; rather the adjustment should be performed in the fully warm curb idle position.

This means the choke is to be fully open, and the carb should be released from the fast idle cam position by tapping the accelerator pedal once. The butterfly valves will be closed in this position.

With this in mind, please re-read the "Throttle Rod Adjustment" Adjustment Procedure section steps 1-6 on the 3rd page of the official FSM document which I posted earlier in this thread, in December 2010. It should now make sense.

The end of the preload spring should normally be in full contact with the adjustable swivel. The preload spring will not be compressed substantially when the adjustment was performed correctly.

The idea is that when you release the lock screw, the preload spring applies sufficient pressure against the swivel to automatically push the throttle rod out through the swivel to the correct resting location. This position automatically eliminates the lost motion in the throttle linkage.

Just to be sure the goal here is perfectly clear, "lost motion" is the condition in which an input to a mechanism yields no corresponding displacement at the output of the mechanism.

If the preload spring is super rusty, so that it has lost metal, you may need to tweak this resting position a bit to compensate for the reduction of push.

I've noticed that with the weaker force applied by a rusty spring, once you finally quit holding the transmission lever (aka throttle lever) firmly forward and allow it to settle to its natural rest position, the throttle valve will open a little.

If you manually partially compress the spring a little past its rest position while holding the transmission lever forward, when you then tighten the lock screw and release the transmission lever, the valve will remain fully closed at rest.

Some people, particularly performance enthusiasts and racers, adjust the shift speed, shift quality, and part throttle downshift sensitivity by forcibly positioning the throttle rod to other than the rest position, but this may leave the throttle valve open and fluid circulating through the transmission when it was intended to be in an unpressurized condition.

If that's acceptable to you, should you desire later shifts, make the throttle rod longer. If you want earlier shifts, make the throttle rod shorter.

BTW, if you ever adjust the curb idle speed by more than 25 RPM, you should revisit the throttle rod adjustment.

If you go to adjust the bands, you may find that a 6-point 9mm and a 6-point 19mm will fit adequately.

Hope that helps!

mine is a 78 Reed, throttle is all the way open.
I'll have to read up on adjusting the bands, I don't know anything about that, but it does have new fluid/filter and is full.