For harsh shifts:
Check - Cause
Throttle Position Sensor - Open or shorted circuit
Vehicle Speed Sensor - Open or shorted circuit
Automatic Transmission Fluid Pressure (TFP) - Contamination or Damaged Seals
Trans Fluid Temperature Sensor - Open or shorted circuit
Engine Coolant Temperature Sensor - Open or shorted circuit
Pressure Control Solenoid - Damage to pins or Contamination

If you did not have this condition until after the rebuild, I would say that the VSS and TPS are fine. It is likely one of the other items that was either installed incorrectly or otherwise damaged during the rebuild.

1-2 shifting rough
 

Swartlkk,
Looked in my Haynes manual for info on Automatic Transmission Fluid Pressure, Trans Fluid Temperature Sensor and Pressure Control Solenoid and couldn't find anything, not even the location of the last two.
Danyboy

This should answer your questions:
http://i11.photobucket.com/albums/a1..._solenoids.gif

The temperature sensor is in the same housing as the pressure sensor.

97 Blazer shift problems
 

Thanks for the diagram, don't know where you got it but it sure helps. Went to see the mechanic who rebuilt my transmission. He drove test it and admitted something wasn't wright, and accepted to re-open my transmission (this will be the second time after last octoboer rebuild).
He had changed the pressure control solenoid but it never helped. Will post follow up on it.
Thanks again,
Dan

1-2 hard shift
 

I am not sure but I think I got the answer for this 1-2 hard shift problem since I gt my transmission rebuilt.
Mechanic told me he installed a 'power kit' in it, whatever that is. Another mechanic at the restaurant today said this knocking I get when it shifts from 1st to 2nd gear was perfectly normal if a power kit was installed in my transmission when it was rebuilt and that my transmission was built stronger and that I shouldn't worry about it.

Sorry to bring back a dead thread but I felt this needed an ending and I have one. Today, just as a precaution before I get a PCM tune, I replaced the TPS on my 2000 blazer. The hard shifting is fixed. What stumped me about this the whole time is that it tested fine. Smooth all the way from .5 to 4.5 at WOT.

If there is an explanation as to why a TPS would test fine and still be the problem, I am all ears as I am kicking myself right now for not just trusting my gut instinct. As of a drive around town, the blazer slowly began to shift better and better until there is no more hard shifts at all. It also downshifts alot quicker as welll.

I felt I needed to put up how it got fixed in this particular situation. Not every solution will be to replace the TPS.

Could have been a bit of tarnish/corrosion on the connections at the TPS that allowed it to test fine, but the vibration/temperature of a running engine caused it to be somewhat erratic...?

I have no idea and frankly I'm too happy to care. I was fully prepared to have my transmission guy drop the pan and take a look when I got around to addressing the problem. I'm glad I didn't have to go that far. More money in my pocket.