3sp, there are lots
yes, the tranny shifts points, vary.
the tranny shifts by:
RPM (governor at rear sends RPM speed related pressure to slaves)
Vacuum modulator shifts by load, if bad or some PO put on the valve from
an heavy car, it will shift harshly, see color code for weight rating.
get the valve of the USPS , mail car, that uses same tranny it shifts easy.
sold at all tranny parts sellers.
the kick down ,or detent valve also set the shift point.
if you accelerate fast the shift points delays.
but on deceleration that is different. (but the other parts stated above can be bad and effect Decal)
the detent valve.
is the cable moving right at the carb.
same for at tranny end.
and its a plunger valve here, see it. is it moving in direct proportion to the carb and if that cable, does it stick? can you push the valve in parked.
is it stuck out.> (all by looking.
replace the vacumum mod valve , cheap and easy.
ill assume fresh Dextron. in pan, no additives gumming up the works.
they put this tranny on many cars, did the last guy use one off a heavy car?
with wrong mod valve.? color marks.
see harsh , here. (fsm quotes all) (pump reg to high?)
1995 AUTO TRANS DIAGNOSIS - HYDRA-MATIC 3L30