Van is stalling (shaking) when its changing gears

no service light is not on

I don't mean a Service Light, I mean a yellow light that looks like an engine or it may say Check Engine. If your van is dying at stop signs, this light should be coming on, when it records the event that is abnormal. Have a code check done, even if it is at a parts store, I bet that there are some codes stored in your computer.