C4 shifts into 3rd late

Good morning,
My 1976 Maverick, 302v8, auto, 73k, orig miles, shifts into 3rd about 55mph...
Anyone know if it's worth installing a new modulator valve ?

 

I'd check vacuum line to modulator first, a small leak can cause late shifts.

Also if modulator has single vacuum connection facing rearward, should be adjustable. Use small flat blade screwdriver to back out adjustment approx ¼ to ½ turn, test drive.

If modulator shows any sign of leakage, replace it.

 

Thanks,
Line looks good, no leaks.
I'll try adjusting today...

 

Installed a new NAPA adjustable modulator; still shifts into 3rd at 55mph... backed the srew out 1-1/2 turns;... still 55mph...

 

When do you want it to shift into third?...

 

Maybe 45MPH...

 

Under light throttle, should shift into 3rd by 30-35 mph at latest.

Assuming it hasn't been modified with a Hi-Po shift kit, probably have either have a sticking modulator shift valve(behind modulator pin) or maybe governor is hanging.

Sorry new the modulator didn't help, it's the first thing to try for late shifting issues.

 

Pin looks worn on the end... I think I'll make a new one; and try that...
Thanks for the replies !

 

make sure you get the length right! check the c4 rebuild thread for the correct one for your application.

 

Worn pin = shorter pin, cause early shift.