Trans Problem

[BUICK87GN]

I'm having trouble with my transmission. I parked the car in April 2009 when I broke 2 teeth off of the pinion in the rearend. I didn't have the money to fix it right away so I kinda just forgot about the car. Just had my rear rebuilt and got a new drive shaft. I went to drive it 3 days ago and it will barely move. It goes in all gears but you have to rev to about 3500 to 4000 rpm to get it to move. Thinking it's the pump. Any help with this will be appreciated.

Thanks,
Ryan

 

[SSedan64]

Have you checked the fluid level?
Check level with the Engine not running then running, if the fluid level drops to correct level the Pumps working.
Check the pressure, 0-300psi gauge, Port above shift shaft linkage to see if Pumps working correctly.