The modulator valve, not bowden cable, will adjust for firmness (clockwise turn) or for smoother shifts (counter clockwise) The modulator valve is on the side of the transmission, drivers side that is, and has a single vac hose connecting from vac amplifier. The center cover of the modulator valve is made of plastic, sometimes green, or grey color, there is a black rubber cap about the size of a dime in the center, pull the cap off, you'll see a circle of slots and a metal bar connecting between, pull the metal bar out, this is simply a tool built in and with it pulled out a 1/4 inch, you can turn to whatever desired position and then push back in to the slots to lock it in position then return the rubber cap.

I used car ramps set up in my driveway making it easier to do as you have to keep testing different positions, both modulator and also the bowden cable too, if your adjusting that as well. Find the happy medium between both bowden and modulator adjustments, that's where you want to be! Too soft of shifting becomes flaring (motor racing between shifts) and this is not good as it heats up the discs inside the tranny and wares them out sooner. Harsher shifts, not too harsh, are less burdensome on those discs but can accelerate ware to the flex discs and center shaft bearing. Shifting points 1-2-3-4 (bowden cable) should occur at or around 2000 rpm. Synthetic transmission fluid is available and may extend tranny life. Dont forget to drain the torque converter too! BB