Nick Bos

Dec 7, 2016
Hi guys,

I have a 1970 mustang with a 302 and a c4 select shift transmission. Recently the transmission has been delaying its shifts more frequently as time passes. I adjusted the vacuum modulator screw to reduce the delay and it has not worked (3 full turns counterclockwise). As of right now my transmission shifts from 1st gear to 2nd at around 2200 rpm and 2nd gear to 3rd at around 2300 rpm (about the same rpm).

Could the bands be loose? Maybe the vacuum modulator went bad? The transmission filter needs to be replaced?

Any advice would be a huge help. Thanks guys!
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