My brother-in-law spent a few years working for an automatic transmission shop rebuilding transmissions. The tranny in my bonne is vacuum controlled. He said I could change the module on the outside of the tranny and alter the shift rpms. Is it true?

yes, it is an easy modification. change it to one that has a screw type front where the vaccuum hose attached. then you can use a small screwdriver to adjust you shift points. The only issue is if you adjust it to high, your car will not allow you to shift down into first. I had one on my old car and when I rebuilt my tranny, I got one for it also. It is a cheap modification and very useful/enjoyable.

Sweet!

NO!

You cannot alter the RPM'* the car shifts at with the vacuum modulator. You can ONLY adjust the firmness of the shifts with an adjustable modulator. The PCM controls what RPM'* the trans shifts at.

So, if you change it to be softer will the tranny last longer?

could, but driving style also affects this. Also, some trannys will just go befoe others.

i thought the softer shifts had more wear and tear

the softer the shift the easier it is on the tranny. The trick is to be nice and gentle.

NO! Again!

The firmer the shift, the less wear on the bands and clutches. This is why transmission shops are willing to install shift kits in transmissions they warranty.

The firmer shift is in the shift for a shorter period of time. This is better for performance, as you're in the power quicker after each shift, and better for longevity of the clutches and bands in the trans.

So this is still a good mod to do? I guess it depends on the adjustment. Any Techlinfo on this?