Transmission, Automatic

Kickdown Switch Mod

Kickdown Switch Mod

Followed Ed's suggestion. Went to Radio Shack, bought a 6A toggle switch, a kit of 20 AWG wire. Since I removed the storage bin under the dash, I had a mounting bracket to drill out a little for the switch. Used the red and black to make a twisted pair and connected the toggle switch in parallel with the stock momentary switch. I tapped into the kickdown wires (soldered and sealed with electrical tape). While I was at it I looked at the throttle linkages but decided not to adjust them since they already looked fairly tight. But I did lube the springs, cables, feedthroughs.

What a difference the lube made in normal mode. The 4-speed auto holds gears longer, kickdown is faster, and shifts are crisper. It stays in first until 5800, then second to 5800, didn't have room to check out third. With full throttle from a stop there is no lag like in normal, and it lays a patch! My 84 928S never did that before. Guess I gotta put those 245/45ZR16's with 16 x 8 's on the rear.
*Jim Komiak

You connect the two switches in parallel. The standard SPST below the throttle is normally open until the pedal closes it. Holding it to the floor keeps it closed. Backing off opens it. When closed, the auto trans will kick down into lower gears depending on engine RPM. The toggle SPST when closed makes the trans think it is kicked down but you can use part throttle conditions. When the toggle is open, the car doesn't know it's there. There is a connector on the bottom of the kickdown switch with two wires coming out (grey and black I think). Pull the connector down off the kickdown switch. Grasping the wires, pull the connector out past the accelerator so you have room to work. You'll have to strip the insulation from them somewhere near the connector. As my earlier post said, I ran a black/red twisted pair from the toggle and soldered black to black, red to grey, sealed them with electric tape. Put the connector back on.


I bought a 86.5 AT some months ago. Great car, fits like a glove. But I found the auto box a little boring at use. So went through the shift cable re-tensionning and kickdown switch bypass (tips taken from this list, thanks to all who posted) making the car much more enjoyable to drive.

The way I've installed the bypass might be of some interest:

I've removed the black plastic unlock button from the shift lever handle and replaced it with a piece of plastic tube with a shoulder into which I've inserted a miniature 'mushroom head' N.O. push-button switch. Ran two small wires from the NO switch, through the lever (had to drill a hole trgh. a second plastic actuator), to a solid state relay put inside the console. Two larger wires go from the relay to the switch under the pedal. The shifter lock mechanism remains completely functional and the switch does not interfere with it.

Now I can activate the kickdown just with a light pressure of the thumb on this button conveniently placed on the shifter handle. This, combined with the 2,3>2,3,D shift sequencing is what resemble the most a manual transmission.

Daniel Parra, Montreal

I just completed the parallel kickdown switch on my shark and the ride is a kick in the pants!! I installed a new stereo when I bought the car, so the factory fader knob was rendered dead and I therefore decided to use it for my switch.

I spliced 18 guage wire into the lines that run to the kickdown switch under the accelerator. I ran those wires under the carpet along the bottom of the footwell and then along the edge by the driver's door. I removed the rheostat that used to control the fader knob by the driver's door and replaced it with a rotary SPST switch. The post on the new switch was too small for the compression fitting inside the fader knob, so I filled the hole with epoxy, coated the post with Vaseline and made a form so the knob would fit snugly on the new post. After letting it sit overnight, I the new rotary switch in the existing hole, tightened it with a threaded washer and put the factory knob back on top. You can't tell by looking at it that it isn't the factory rheostat.

It was a simple job, and really satisfying to make it so unobtrusive in the cockpit. I kept the original rheostat and will add a new knob ($5) to my next order from any of "the big three" so that this mod could be easily replaced with the original equipment. Total cost for the job was ~$10.


Jason Butler
85 928S Euro AT <- sometimes

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