Isn't there an e-clip or C-clip on the shaft? That is a usual method of holding them on. Look where the shaft and the motor connect VERY carefully, perhaps with a magnifying glass. It could be a force-fit, but I doubt it.

__________________
Semibodacious Transmogrifications a Specialty

1990 300D 2.5 Turbo sedan 171K (Rudolf)
1985 300D Turbo TD Wagon 219K (Remuda)

"Time flies like and arrow, yet fruit flies like a banana"
---Marx (Groucho)