1997 Oldsmobile Regency Q&A

1997 Oldsmobile Regency Question: Transmission jerking when shifting

Transmission shifts funny from 35-55 if under a slight load. Shifts fine if not under a load and seems to shift ok too if I'm rapidly gaining speed opposed to gradual speed gain.It would jump back and forth when trying to upshift, if I tried to gain speed it evenually shifts up ok and runs fine. Gotten more pronounced the past week or so. It is fine at slower speeds even climbing a steep street. I'm really hoping this is not serious. I put 1/2 qt of fluid in it because it was low but did not help. Could it be a modulator? No engine light on or other lights. Seems not to happens so much when it's cold. -
Answer 1
First thing is to put something in the line ( pencil ) and plug it to see if the trans shifting problem is because of the vacuum leak. Then try to find a diagram of the vacuum lines, maybe http://images.google.com/images?q=1997+oldsmobile+regency+vacuum+diagram&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&ei=AsBLS6TvJ4TkswOZ1cj1Dw&sa=X&oi=image_result_group&ct=title&resnum=1&ved=0CBwQsAQwAA -