Hope I'm posting this in the right forum room, apologies if I'm not... With my kustom '57 finally running, I've noticed its TH400 'p***ing gear' isn't kicking in like it should, it's from a '67 Pontiac Catalina series. Has a male vacuum port on right-side that I can't figure out where a hose should go to (Olds 350 has Edelbrock carb), advice appreciated..
This should be in the "traditionally styled forum" I think. The modulator needs manifold vacuum source. This controls your line pressure- The electrical connection near the linkage arm needs 12 volts at WOT or very near WOT. This controls the kick down. There's various ways to accomplish that. Some factory and aftermarket but they are all tied to the accelerator at WOT. Some have an attachment to the pedal under the dash, some are tied directly to the throttle arm of the carb.
Thanks! What is WOT? I do have a new modular, the line going to manifold vac source. This is a second male port coming from the trans, though, that's the one in question. Thanks again.
There should only be one vacuum fitting on the trans, which is the one on the vacuum modulator. How about giving us a picture of the thing you're asking about? The electrical connector is for the electrical switch that should feed power to the transmission at Wide Open Throttle. Some of the early Th400 transmissions have two electrical connectors next to each other....some of these are for the torque converter stall, others are for emissions controls. We'd need more info on the trans to help you figure out what you have, if your trans has the two pin connector.
For a TH400 kickdown switch you might consider using a GM# 1242101. It mounts under the dash near the accelerator lever. You'll need to check to see if your car has provisions for it though. There's some pictures of it at the top of this page: http://www.bing.com/images/search?q=GM+1242101&qs=n&form=QBIR&pq=gm+1242101&sc=0-0&sp=-1&sk=#a
Tim, "WOT" stand for "Wide Open Throttle" just like "WFO" = "Wide ******* Open" I need to get the kickdown switch operation on the T with the TH350, too, so I will be watching this thread...
As I did before.... only because I lost my lithograph set... hopefully you will see the pictures showing that which I am asking about... above the red shift cable is the single-prong tab on drivers' side.... above-left of the modular you should see that other male port I was talking about, coming from the rear-top of of trans...
The other "vacuum fitting" is actually the vent, leave it alone, it is supposed to be like that. The single prong electrical connector is the kickdown, you need to give it 12v when the pedal is to the floor.
Tricky part is I don't have rod-linkage for the pedal, it's a s**** pedal hooked up to cable. A friend and I were just brainstorming about wiring the prong to a shifter-mount ****on, to manually prompt the kickdown for the "p***ing gear". For the rest, I'll just have to have my (new) vacuum modulator adjusted, to reach higher gear on Highway 101. Just recently got the whole mama running for the first time in this truck, tuning to be done. Stuff I'm learning/ thought I'd p*** it on, while on here.
here's 70,000 or so pictures of turbo 400 kickdown setups. 3 out of those 70,000 have a ****on. There's OEM and aftermarket mixed in. https://www.google.com/search?q=tur...=isch&tbo=u&source=univ&biw=320&bih=504&dpr=2
Number 6 photo on the 70K or so... for others thinking of this, too... thanks again... blyme we're back to relays, heh heh
As others have said, the TH400 kickdown is electricaly controlled. Some use a switch neat the carb others use one near the throttle pedal. I used onr near the throttle pedal. It just takes 12 v in, when the pedal goes to WOT, vloses the switch and supplies 12v to the solenoid inside the transmission. A simple thing to rig up
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