C4 1-2 shift question

[BroncoKelley]

The C-4 in my 74 has a hard 1-2 shift. It doesn't matter if I accelerate lightly or am in the throttle. Hot or cold it is the same. The 2-3 shift is normal and my garage shifts are normal. Since I got the Bronco I have serviced the transmission, replace the shift selector seals and installed a green stripe vacuum modulator with 1 turn clockwise to slightly delay the upshift to suit my liking (originally had a 2-port red stripe modulator). The fluid is type F, is nice and clean and the level is correct. The 1-2 shift was always hard before any of these items were done.
Does anyone have any clue as to what i should look for? Back in my GM days we had problems with the 1-2 accumulator (SERVO) springs breaking causing a hard 1-2 shift.

 

[Brent13]

I have same year and same trans, and same issue. That first to second shift is brutal! If I baby it it is not too bad, but still very snappy. I have no input as to a fix or even if normal, but I'll be following this post.

Brent

 

[Viperwolf1]

There could be a problem with the servo or there could be some modification that was done to the valve body. You can remove both of those without pulling the trans out.

 

[mpboxer]

Would a shift kit cause this i.e. Transgo or similar? To a certain extent is it better for the transmission for nice crisp shifts instead of slippage? I subscribed too, I don't think mine is as severe as you describe, but when the PO had the tranny rebuilt they added a shift kit.

 

[treihesse]

Yes a shift kit causes a very positive shift. I have a transgo and you know when it shifts

 

[Viperwolf1]

Would a shift kit cause this i.e. Transgo or similar? To a certain extent is it better for the transmission for nice crisp shifts instead of slippage? I subscribed too, I don't think mine is as severe as you describe, but when the PO had the tranny rebuilt they added a shift kit.

It could depending on the kit used. Most kits have you drill the separator plate. It doesn't take much enlargement to make a big difference in feel. Slow, drawn out shifts will wear clutches faster. Wear doesn't happen when they are disengaged or locked up, only when they are slipping.

 

[JWMcCrary]

Yes a shift kit causes a very positive shift. I have a transgo and you know when it shifts

X2 same here.