If it has over 100k on it, you might reseal the front servo and add .25mm of shim to the apply piston. There is a measuring device for this but, the thing wont fit in the servo opening with the unit in the car.
These servos leak and the band wears creating more clearance which creates harsher 1-2 shifts. There also is a for worn bores in the case that involves chambering a 30 deg angle behind the seal (not the pin side, it'll blow the seal off) to allow fluid pressure to enhance sealing ability.
Whoever suggested checking the modulater was dead on as well, however that will rarely affect a single shift. Modulator and bowden cable adjustments are critical to proper shifting.
Project Smoker, '87 603 powered wagon
Hauler, 96 CTD can you say torque?
Toy 73 Cougar xr7 convertible
Acme Automotive Inc.