Jimmy_B

It appears that the P.O. of my 72 CS did not install the electric kickdown when converting from the 350 trans to the TH400. There is a hole in the firewall with a grommet that is empty. There is also a circular eyelet on the gas pedal arm that is empty as well. I am assuming either of these locations (or both) is where a cable ran through for the 350 turbo trans.

My question to the forum is: Is it worth hooking up the electric kickdown switch and harness to the TH400? I have the Hurst dual gate shifter and can shift down manually if needed now. Are there known problems with the electric kickdown? I'm just wondering why this was never hooked up.

From my understanding, if I hook this up I will need the switch,bracket to hold switch,wiring harness and solenoid. Has anyone here been through this installation? Are the retrofitting kits worth the time and money, or should I stick with original part configuration?

Thanks

Intragration

I had the electric solenoid in the transmission fail, it prevented it from shifting. I don't think this is a common problem, and I think this part could fail even if you don't have the circuit hooked up. It should already be inside your transmission. I'd hook it up, I like having a functional kickdown. I don't know how easy or hard it would be to track down parts. In case you can't find the Olds parts, there was also a setup that mounted the switch on the carburetor.

2blu442

You need a different gas pedal assembly with the switch bracket on it. I think it's a good idea to correct this. If you get in a tight spot and need to scoot to avoid a crash, it would be nice to have the kickdown working. I don't have an extra one at the moment, but there's lots of members here with spare parts. I'd suggest you create a parts wanted thread for the correct pedal with switch. Then you can add the wiring, the Chassis Service Manual would help with that.


John

citcapp

This is what I used on my 57 Olds with the 455 and turbo 400. Easy to install

http://www.summitracing.com/parts/bmm-20297

MDchanic

And, as a quick look at those Summit parts will show, a person who prefers to save money, rather than time, could cobble the same thing together from parts in the tin cans in the garage, so, though it looks like a neat kit, the $45 cost need not deter you if it's more than you'd like to spend.

- Eric

citcapp

I agree with this. Oldsguy did the same thing on his 46 with pictures of mine which I bought on flea-bay for $14.00 + shipping

joe_padavano

All you need is the stock switch, bracket, and correct gas pedal (and you can even just modify your old pedal). The wiring is already in place in the car. Four screws and two connectors and you've got kickdown. Just do it.

Jimmy_B

Thanks Everyone, I think I would prefer the "stock" route to the kit. Here is a picture of my pedal assembly now. Can someone post a picture of the correct pedal with switch (anyone with a TH400 w/switch)

Thanks again...

joe_padavano

If you go to Google Images and type in "TH400 kickdown switch", here's one of the images you get:

joe_padavano

By the way, if you simply cut off the extra tab on your current pedal, you don't even need another one, just the bracket and switch, which are available from repro houses. And to correct something I wrote earlier, there are only TWO screws, not four. Sorry about that.

Jimmy_B

OK, so thanks to Scott (oldspackrat) I will be receiving a used kickdown switch and bracket in the mail.

I just want to be sure that removing the tab on the pedal linkage where the cable runs through will result in me having the correct pedal assy to fit the new switch and bracket.

If anyone has done this, please advise before I go and ruin a perfecty good gas pedal assy.

Thanks

oldspackrat

Jimmy,
The switch & bracket are in the mail to you. I'd see if the switch hits the extra tab on the pedal before I do anything. It might clear it & you might not have to do anything to it, but I'm not sure.
Thanks for your business!
Scott

matt69olds

The wiring is already under the dash for the switch, I'm pretty sure the wire coming from the wiring bulkhead connector to the trans will need to be added for a factory look. If the correct factory look isn't important, about 8 ft of wire and a few hardware store connectors will get you in business.

Jimmy_B

OK, the switch is all wired in and the pedal has been modified to activate the switch properly.

Problem is... the kickdown is only working some of the time??? Also, it seems to work less frequently the longer I drive it.

Any ideas?? Bad switch? Bad Solenoid?

I will be replacing the Trans pan gasket sometime soon, so maybe that would be a good time to replace the solenoid if need be.

joe_padavano

Sounds like the solenoid is bad. If it hadn't been used in a while, it may be gummed up. As the trans oil gets warmer, the crud in the solenoid gets soft and sticky, causing the intermittent (and more frequent) failures). While the pan is off, also check the internal wire and connector in the case for any signs of damage.

Jimmy_B

Thanks Joe !

I will replace the solenoid and check on the wiring and connections inside the transmission.

timothypaul

Seems like we were doing the exact same project at the same time. I did this on Saturday.

Did you check with an ohm meter to make sure the switch was working. As I pull the peddle back on mine, sometimes it doesn't engage because the tab on the solenoid instead of going straight back, pushes down a bit. I'm going to have to tweak mine a bit.

Curious - I had to move my throttle cable to another hole that was about 3/4 inch further up to keep the accelerator cable from binding. Did you?

joe_padavano

That's because whoever put your car back together when they swapped in the motor and TH400 did it incorrectly. The accelerator cable ALWAYS goes in the top hole. The lower hole is only for the TH350 kickdown cable.

timothypaul

Yea your right Joe. The brain surgeon actually just cut the cable on both ends and left the remains in there!