Missing a Speed?

[mustangII460]

The vacum modulator is at the right rear corner of the trans pan area. Make sure the vacum line goes to a good vacum source on the intake manifold. Usually its plugged into a vacum T at the back of intake.

The modulator will control your upshifts. The modulator is round looking shiny thing with the vacum hose directy into the center backside of it. To adjust the shift points your adjusting the vacum pressure. If you pull off the vacum line you can use a small flathead driver to turn the screw, the screw is what the line goes over. ONLY TURN 1/4 turns at a time, drive. Check EVERYTHING first!

Im willing to bet you have a vacum line loose/pinched somewhere. It sounds like it to me. Alot of times your tranny will also spit fluid out as well with the modulator not working.

If you replace the modulator DON'T lose the little pin/actuator inside of it. Carefully replace it with new mod.