Severe Hard Shifting

[justinhill7714]

I have a 78 f150, 3 speed automatic, with a 302. My problem is when I shift from park to any gear, I get a mean kick, Reverse feels like I dropped 3 inches and Drive up 3 inches. Also while driving, my shift to 2nd and 3rd kick mean. Trying to figure what causes that.

Thanks,
Justin Hill

 

[DNFXDLI]

U-joints and rear end ok?

 

[fatherdoug]

Could be differential, or U joints(slop), or could be rebuild time. Hesitation between putting truck in gear, and having the truck move, is an indication of tranny rebuild time.

 

[Fellro]

Check motor mounts and trans mount. Plus, please define "kick", as in shift hard, or like someone hit the floor pan...

 

[m78]

Whats your idle rpm ?

 

[justinhill7714]

Initially is a high idle. When warmed up, idle drops. it's not much of a drop. When cold, the shift to reverse is rough, like a thud, and drops. 2nd gear shift hard. 3rd just follows not as hard.

 

[SuperCab]

If you're not idling low enough it will make a hell of a kick

 

[Fellro]

It'll kick pretty good with a high idle, but doesn't explain the later shifts. Vacuum leaks would explain both... especially if it is the vacuum hose to the transmission vacuum modulator.