the 1-2 shift in my tranny sucks, it is slow and has a bit of flare(rpms go up between shifts), but the 2-3 and 3-4 shifts are normal. i believe i read that this can be cured with a shift kit because a spring is broken or something.
is this true?
what else could cause this?
and can you install a transgo kit without removing the tranny?
Thanks!

Edit: this is a 700r4, and the fluid smells good and there is no sludge or crap in the pan.

 

it was a broken 1-2 accumulator spring, picked up a new one from a local trans shop along with a 'vette servo. put the new spring in now it shifts great at partial throttle but still has a slight slipping feeling at wot though. the 2-3 shift is great at all throttle openings. the 'vette servo has yet to go in becaus i'm having a hell of a time getting the lock ring off of the cover

 

yes the servo snap ring can be very stubborn after so many miles, might as well pick up a new one, just use a screwdriver and a hammer, pull the cover out a little bit then and then cut the o ring seal, usually green, pull the rest of the way out. may have to hit the cover with a rubber hammer to try and loosen it up a bit first, then try and get the snap ring out.
yes a shift kit can be installed with the trans still in the car, but if it is slipping, a shift kit wont correct it.

 

the slipping feeling was because of the broken spring.