tomcat

I installed a kick-down switch for my '85 4-sp auto. I have some questions RE: what is it supposed to do? If my trans ok?

I thought the trans would behave normally (upshift) with the switch on, but it would downshift before the switch under the "go" pedal is engaged. But still upshift when not being agressive with the accelerator. Instead, when on (parallel switch), the trans downshifts and stays in the lower gear - like I just downshifted with the level. When starting out with the p. switch on, the trans stays in 1st and, I think, after the cars moves down the road a little, the trans starts slipping as the revs increase (no upshift). But I didn't let the engine revs get too close to redline.

I can see the need for the switch when going around 30 and the trans doesn't downshift when stomped on. Is proper use of the switch to flip it on only when you need a downshift? The way mine is working, it doesn't seem much different than locking the trans in gear with the lever.

Pls let me know how this is supposed to work, thanks.

Alan

I think you want to have a momentary switch not a locking on/off. You should just be using the switch on a demand basis for added vroom!/bwaah!

You should get 1st gear starts and maintained gears through to the top end of the rev range before upshft - push it a bit and make sure you get your upshifts before the rev limit. You probably won't enjoy being in kick down the whole time...

Alan

PS... but bear in mind I don't even have an auto....

Ispeed

I used my kd switch on my '89 a/t in the SITM twisties, and it was more aggressive and stayed in a lower gear longer. And leaving it in "3" as well.
Not a concern any more...

tomcat

Thanks for the info. I think I'm going to have to change the switch to a momentary before I break the switch lever in the "on" position.

Alan: Having an auto is fine, especially without cup holders. But I find myself grabbing the shifter when approaching corners. I'm jealous and wish I had a manual sometimes. But then again, a manual might get me into a lot of trouble. I feel like I'm only getting half of the driving experience.

Garth S

I assume that you wired a SPST switch in parallel to the momentary contact switch under the throttle pedal: when 'off', the SPST has no effect - when made 'on', the kickdown circuit believes the throttle is always wide open (WOT): this is one of the conditions to be met to promote downshifts.
It's that simple - and you should be able to drive normally, enjoying regular shifting of all four gears with the bypass switch left on. The only function of the switch is to require less than full throttle to promote downshifts .... as long as everything else with your transmission and its adjustments are on spec.

Here's an old post to show how easily it can be done on a trial basis: the effect of the jumper is identical to a SPST switch closed .... you do not want a momentary contact switch.

tomcat

Garth,

I had a hard time driving "normally" with the switch on. With it on, when I started out in first gear (never had the problem of 1st gear starts) with a light accelerator, the trans seemed like it was slipping at the rpms got higher. Felt like I was engaging a clutch.

When I turned the switch on while driving in a higher gear, the trans would immediately downshift and seemed to never upshift even when I let up on the throttle completely and then pressed down again.

Maybe I just need to let the trans warm up a little and try again. Nomally, w/o the switch, at light acceleration my shift points are around 2500rpm. If leaving the switch on moves the shift points to over 5000 (such as during hard accel) , I think I'll keep the switch off until I need it.

By the way, your trick to close the switch for a test run is a great idea. But it would have worked better before I cut the wires.

Shane

After I got a Jager shift **** I quit using the kickdown and just shifted it manually.

Vilhuer

Whole point of the switch is to keep gearbox in as low gear as possible. It should change to higher gear right before redline. If this is too high change point permanently on switch is probably too radical device for you.

Garth S

John,
The bypass switch is to be spliced across the two leads ( in parallel) prior to the throttle switch: I'm certain that is how you did, but am equally confused with you on the results.
On my car, with the switch engaged, the transmission behaves normally - with the exception that downshifts occur with far less than full throttle (WOT).
The car is more responsive to input - to the point that it is only rarely used in town When pushed, all shifts occur at redline, regardless of the bypass switch selection.
With the switch off, how does your transmission behave? Does it shift at or near redline when pushed? Do downshifts occur when called for by the throttle? Is it one that starts in first gear from rest? etc - maybe this could give some insight, for the 'regular' shifting behavior is sensitive to control cable adjustment, vacuum modulator setting, fluid level, ...
An alternative is the Jager shifter Shane noted: it may be a momentary contact type/maybe not - I do not know. Regardless, I'd start by reviewing shift behavior with the switch open. - and hope for someone with real expertise to chime in ...

tomcat

I'd like to get the type of performance that Garth is talking about.

It's raining today and I'm out of town this weekend so I am going to fiddle with the trans next week.

I have never had any forementioned problems with 1st gear starts. Can get to 30-35 mph and 4th gear during moderate (granny) acceleration. And can get redline revs if pushed. But I am trying to get downshifts without mashing the accelerator.

Here's my question. If I am getting consistant 1st gear starts due to the PO making the appropriate adjustments, would the parallel kd switch be a little out of wack? I'm wondering if slackening the trans cable (near the radiator) now would allow me to get the upshift/downshift behavior (as described by Garth) I am looking for with the switch always on. Anyone ever experiment and seen what interactions there are between the kd switch and varying cable tension?

bdstott

AFAIK, ALL auto transmissions upto mid 87 will start in first by design. My 86.5 always starts in first. In 87 they changed it to try to make it a little more fuel efficient.

tomcat

Thanks Brian. I think I am going to install a momentary switch and pay more attention to model specific info.