FAZ442

Hey guys,

I have been looking into playing around with the adjustable modulator on my th400 and was just wondering if anyone has done this or not and if its worth even tinkering with.

I have an adjustable modulator on my TH 400 and supposedly you can change the shift points a bit by simply turning the screw in the modulator. I have 373 gears and my trans shifts into 2nd gear at about 10 mph if that. will adjusting the modulator help any in performance or gas mileage?

Just wondering if anyone has done this before.

Thanks in advance for your experiences

455man

I've done it. It doesn't seem to make a big difference.

oldcutlass

The modulator has nothing to do with heavy load shift points. It controls them under very light throttle. You can change the shift point by adjusting the screw inside where the vacuum hose connects, you may be able to get 5-10 mph out of it! The governor controls shift points at WOT.

FAZ442

Sorry if I wasnt specific enough but that is the same screw I was talking about in my initial post about adjusting. So by simply turning that screw where the boot goes you can get 5 to 10 miles out of it?

Is that at each shift point?

matt69olds

The modulator can adjust shift points up or down 2-3 mph. If you want to make a bigger change you need to change the governor. On a TH400 its on the pass side behind a square cover than is held in place with 4 bolts. I would suggest getting a spare governor and a B&M governor calibration kit. Make you adjustments to the spare governor, that way if you get it to far out of adjustment you have the original to go back to. It takes a lot of trial and error to get the shift point where you want them.

67442HT

Turning the modulator screw clockwise, in, will raise the part throttle shift points and firmness. Try turning it in a half a turn at a time until you like the way it shifts. You will like driving the car better after you do this.

oldcutlass

I would go 2 turns clockwise. A 1/2 turn won't do much.