Ford Muscle Cars Tech Forum banner

1 - 3 of 3 Posts

·
Registered
Joined
·
92 Posts
Discussion Starter · #1 ·
I'm running a 460 with a C6 auto tranny, and I'm having a little trouble with it. Basically, if I'm at WOT it won't shift out of first at all, I have to let up slightly. I read on another board from someone who was having a similar problem, and they were told to install a shift kit. Kind-of a newbiw when it comes to antything transmissions, so um, what is a shift kit, how much would one be(typically), how does it work, how hard is it to install one(If I can tear down/build up the motor, would the shift kit be easy enough for me to install?) Any help would be appreciated
 

·
Registered
Joined
·
283 Posts
You trans has two shift point controls. One is a vacuum modulator, which is fed a signal from the intake manifold, this is what regulates your part throttle shifting. The less vacuum it sees, the higher it will allow the motor to rev. When you have the motor at WOT, the vacuum signal drops to almost zero, and the governor in the tailhousing is what regulates your shift points. They come from the castory calibrated to gear ratio, tire size etc. If your trans is from a truck that had 4.88's and you've got it in a car with 2.70's, then you'll run over your oil pan before that tranny will shift. Basicly, it is looking for a certain rpm of the driveshaft to shift at. When you let off the throttle slightly, you are increasing your manifold vacuum signal to the modulator, and it then tells the tranny to shift. A shift kit probably won't help this situation, a governor calibration kit is needed. All that this entails is removal of the crossmember and tailhousing, and changing a couple springs.
 

·
Registered
Joined
·
5,551 Posts
....And yes, you can re-calibrate the governor springs to allow the motor to rev to whatever speed you want before it shifts. You might have to do some spring "stretching" to get it just right, but you can leave it in "drive" and drag race. I've done it, but with the stock springs, just stretched a little. Shifted @ 5600 rpm.
 
1 - 3 of 3 Posts
Top