TH400? Kickdown? 67-442

[Flye]

Anyone out there that can give me a quick lesson on kickdown hookup for a 400? I've seen an online article from Hi Performance Pontiac on how to wire a B&M switch. Is that all i need to try to follow?

[joe_padavano]

Originally Posted by Flye

Two questions:

67 442 (real car): Automatic, would it have come with a 400? or 350? (or did they come with either) I believe the seller thought it was a 400. It has an electrical/wire running into driver side if that is a clue.

Kickdown: It looks like 350/400 have different kickdown mechanisms. There is nothing at carb that I see, mechanical or electric, but I've been chasing other issues so far, so I haven't spent a great deal of time looking.

would it have been on carb or at accelerator somehow?

Anyone out there that can give me a quick lesson on kickdown hookup for a 400? I've seen an online article from Hi Performance Pontiac on how to wire a B&M switch. Is that all i need to try to follow?

The TH350 didn't exist until 1969. The TH400 was the factory automatic trans for the 67 442. The TH400 uses an electric kickdown, the TH350 uses a cable. Your 67 442 should already have a kickdown switch built into the throttle linkage bracket on the firewall near the master cylinder.

The kickdown circuit is pretty simple. Fused +12v is applied to one side of the switch. At WOT the switch closes, sending +12V to the trans. This activates the solenoid valve inside the trans, which switches hydraulic pressure to cause a downshift.

[Flye]

Thanks.

I came home at lunch and followed the wire from trans. It goes to exactly what you described. In this case it is a round 'pod' looking thing that connects to the throttle linkage.

All wires are there and connected.

The kickdown isn't working, so something isn't working right.

[joe_padavano]

Originally Posted by Flye

Thanks.

I came home at lunch and followed the wire from trans. It goes to exactly what you described. In this case it is a round 'pod' looking thing that connects to the throttle linkage.

All wires are there and connected.

The kickdown isn't working, so something isn't working right.

It's easy to troubleshoot. Check for power to the switch with the key in RUN. Check for continuity across the switch terminals with the throttle floored. Check for power to the trans connector with the throttle floored. If all that is good, then the solenoid in the trans is bad. This is easily replaced if you drop the pan. One bolt and one wire hold the solenoid to the valve body.

[Flye]

If it comes out that the switch is no longer good, can you still buy a switch that fits?

Thanks for your help on the troubleshooting!!

d