Technical C4 Modulator adjustment.

My C 4 has an adjustable single hose modulator in it.

From what I understand adjusting it will delay the upshift time a little bit but I’m unclear what effect if any it has on the downshift timing while slowing down.

Anyone have any experience with these things?

 

The governor controls down shift on coasting.

 

The adjustment changes how the spring in the modulator reacts to vacuum. Under low vacuum conditions, such as upshift, you'll notice a slight difference when you change the adjustment. Under high vacuum conditions like deceleration, it's not likely to make any noticeable difference. As he said, the governor is in charge of that.

 

Okay thanks I understand. It’s up shifting fine, it’s the down shifting that seems a little bit delayed , it seems to be dropping down to second at an appropriate speed but it’s not shifting down to first until I’m almost stopped coming up to a light.

Maybe that’s normal it’s been a long time since I used these old transmissions.

 

I would not worry about it...the Fords were strange, with their green dot, etc. Although the later ones were pretty normal. you didn't say what year the transmission is.

 

It’s out of a 1972 Maverick, it was behind a 302
No green dot.

 

Thanks.

What I was implying, is that Fords automatic transmission philosophy seemed to be to start in Second gear if possible...so it makes sense that they would delay the 2-1 downshift till the lowest possible speed.

 

If it starts out in first that is a good sign.

 

Started in 58... you had your choice..

 

Normally you shouldnt even notice the 2-1 downshift. It downshifts at around 5 mph.

 

There is the problem, he only slows down to six miles per hour for stop signs....

 

He doesn’t wear out his brakes . Less work more driving.

 

Just as a follow up, I didn’t bother with any adjustment.
Now that I have the fluid reading full on the dipstick (it only needed 2 litres of fluid) after having 9 litres already in it.
(I had to get some more)
So a total of 11 litres.

My RPU seems to run better and function better each time I get it out for a run.

The transmission is working perfectly and doing what it should.

Thanks for the help and the fun too