One problem related to steering knuckle spindle has been reported for the 1998 Toyota Sienna. The most recently reported issues are listed below.
The vehicle's right rear wheel along with the axle/spindle came off after the spindle/axle snapped while driving at high speed on I-10 westbound near pomona, CA on 9/22/2000 night. The vehicle went totally out of control and crashed into the concrete center divider and finally landed on top of the concrete divider with direction facing eastbound.