Having trouble with the turbo 400 in my 71 w30. I had it completly rebuilt a couple years ago and only have less than 2000 miles on it. It shifts nicely when accelerating normally but under hard acceleration it wont shift from first to second unless you let off the accelerator. Also if you are running along at say 50mph and floor the pedal the trans will drop into 1st gear instead of second. I've checked the vacuum line and replaced the modulator but found no change. Any Ideas? I'm convinced it shouldn't be anything major because it hardley has any miles on it but not sure.

 

Detent switch adjustment?

 

Sounds like a governor problem. They have 'fly weights' that are centrifugally activated. It may have the wrong calibration. Changing the weights will affect it's calibration allowing it to shift at lower or higher rpm at WOT. The vacuum modulator will control shifts under normal throttle settings until vacuum is lost (i.e. WOT).

 

There are 2 sets of weights on the governor.

 

 

I guess I'm a real novice in that department. Do I just replace the governor or change the weights.? Is there a definate way to go about it or is is trial and error? thank you for any help.

 

It's a lot of trial and error, B&M makes a kit with springs and weights. If you google governor mods Turbo 400. There is a lot of info on this.