There are two belts. Here is how to change them both. Pictures included.
http://www.justanswer.com/questions/1qyrs-2004-scion-xb-change-alt-power
Scion xB was created in 2003.
The 2008 Scion xB has a total of three main belts: one serpentine belt that drives multiple accessories like the alternator and power steering, and two timing belts. The timing belt is crucial for synchronizing the engine's camshaft and crankshaft. Regular maintenance and replacement of these belts are important to ensure optimal engine performance.
change the oil
The 2005 Scion xB has 16 valves.
The 2013 Scion xB has 16 valves.
The 2014 Scion xB has 16 valves.
The 2006 Scion xB has 16 valves.
The 2011 Scion xB has 16 valves.
The 2009 Scion xB has 16 valves.
The 2008 Scion xB has 16 valves.
The 2012 Scion xB has 16 valves.
The 2010 Scion xB has 16 valves.