Is there a way (an easy way) to set the shift points in a TH400? I would like to get a little more RPM out of the engine before it shifts. The car has plenty of go, but always shifts at about 3k. MikeMc712008-03-03 09:21:12

There are two ways to accomplish this. First is to screw the adjustment screw IN on the modulator. If your trans has the huge, coffee-cup sized modulator, get rid of it and replace it with the smaller sized mod, available at most any parts store, or trans shop.
Adjusting the mod. will effect ALL of the shift points, tho, not just WOT.
The other way to tailor the shift points is by changing the governor weights and springs. This is a little more involved, and it may take several tries before you get the results you want. There are "kits" available for this, too.
Another thing you may wish to check first is the kick-down solenoid inside the trans. If it is leaking, or otherwise not functioning properly, it will allow WOT shifts that are too soon, as well as passing gear downshifts that may not happen at all at higher road speeds.



btw...if you are mainly concerned with "normal driving" shift points, and not really the WOT stuff, then adjusting the mod. will prolly fix ya right up. The mod only has soo much adjustment, so ya have to be careful to not bottom out the screw.

Thanks Joel, I ask because I will be pulling the pan and fixing the kick down and thought I could do all of this at one time. I don't know yet if its the solenoid or the switch itself, but the kick-down hasn't worked since we got the car. Replacing the solenoid, switch, and modulator might just be the key!

Mike, be aware that there are two different kinds of kick-down solenoids. Depending on whether yours has ever been replaced in the past, it will prolly have the larger one, with a oval-ish "can" on it. The replacement will be a smaller size, kinda square, without a cover/can. They are interchangeable, but...the older style takes a thin, sheet metal "gasket" under it....the newer one does not. Don't try to use the old gasket on the new solenoid...it won't work. The newer solenoid style has a built-in seal on the bottom of it...just bolt it on and go.
You may want to check to see if the solenoid is even getting any power. To do this, put a test-light, or voltmeter on the wire that goes to the connector on the driver side of the trans. With the key on(engine off), mash the accelerator to the floor, and see if you get 12v at the connector. If you do, then the switch, and the wiring to the connector are good. If you do NOT, first check to see that the switch is actually touching the pedal when you mash it to the floor. Then check for 12v(key on) at one end of the switch. If there is no voltage at the switch, check all of your fuses.
Sometimes, you can adjust the switch to hit the pedal with no problems. Other times, you can't for some reason or another. In that case, you can get a short piece of 3/8" rubber fuel hose, and slip it over the little arm/dowel on the switch that the pedal hits. This will allow the switch to touch the pedal....usually. It also is a good trick if you just want passing gear to kick in a little quicker.
On my '74, it has the same switch on the pedal to activate the cowl induction hood flapper. I put the hose on it so it will open up without having to go to full throttle...I just like it better that way.

Thanks Joel. The switch seems to be sticking about halfway through its full stroke, so that may be part of the problem. The maodulator is brand new AC unit ( go figure), and I adjusted it as you said. I will drive it tonight and see how much of a change it made.