Hard shifting tranny??

My automatic transmition on my 96 blazer shifts hard on the 1st to 2nd gear shift, it seems to only jolt when in lower RPM's but if im on it and it shifts at 5,000 RPM's it doesnt jolt it will shift smoothly. And sometimes when it is really hot out it get worst and it will jerk me back into my seat, What should i do? Any help would be great.

ok the shift problem is probably the (pulse width modulator torque converter control solenoid) pwm/tcc solenoid, simple and easy to change, drain trans fluid (drop pan . pump out, ..)may as well change trans filter also, will need 5 qts of tran fluid, the filter pulls down, may have to get pliers to get the o-ring seal out, ordered tcc pwm solenoid from bulkpart.com,,,,27.75 shipping included, located in dallas, tx, makco dist., the old one is cut at wire's to remove , new one is spliced to old wires and screws in, it is really that easy, first time i have dropped transmission pan ever and looked up there ,always thought things would come flying out of the tranny.i also changedd the kick down solenoid, 15.00 part , the 4l60e transmission has had probs with that also, but the tcc/pwm is your problem, instructions are good and clear as how to change,

Thank you for the help.

Is your check engine light on? ,does it shift hard all the time or periodicly from 1st to 2nd. hows your shift from 2nd to 3rd? If your shifting hard you must be kicking out some kind of acode I would take it to parts america.or Auto zone They will run your codes for free. This could be a Throttle position sensor,which is much easier then dropping a tranny pan.

No my check engine light is not on, and it always shifts hard from 1st to 2nd all the other shifts are fine. I will take it to auto zone and have them try to pull some codes anyways. thanks