Modulator valve adjustment

[junkyardjeff]

The C-4 trans in my 55 sunliner is now shifting a little sooner with the gear change from 2.79 to 3.00,I presume most of the modulator valves are adjustable so do I turn it in or out to get it to take a little longer to shift.

[Crosley.In.AZ]

The C-4 trans in my 55 sunliner is now shifting a little sooner with the gear change from 2.79 to 3.00,I presume most of the modulator valves are adjustable so do I turn it in or out to get it to take a little longer to shift.

If the modulator is adjustable, there with be a small blade type screw inside the nipple where the vacuum hose attaches.  Turn the screw "in" clock wise as you look at the modulator for later shifts.  That pre-loads the internal spring more against the vacuum pull