Thanks for the link. I knew the basic concepts on how the planetary gear works, but the pictures helped clarify how things might look inside. When I pick up the vehicle I'll see if I can get more information as to what exactly broke. Final price was actually $1150 for the transmission and labor, plus I opted for the 2 year warranty for an additional $200. Hopefully I'll be getting rid of the van within 2 years, but who knows.