2004 Sienna Timing Belt/Water pump notes.

2004 Toyota Sciena timing belt and water pump removal and installation notes:

There are more complete web sites and video's of this procedure, but I wanted to document a few points I figured out.

First of all see my post regarding the side mounting bracket flaw.

Next, the engine is mounted so close to the side wall of the engine bay that removing the rear cam gear to take off the timing belt cover back is difficult without the special tool to hold the cam gear.  My solution was to not remove the rear timing gear and only loosen the rear cover so the water pump could be removed.  I did this by removing the front timing gear with a powerful torque wrench.  I then removed all of the bolts to the rear timing gear cover.  The bolts behind the rear cam gear are accessible by rotating the cam.  Do not be surprised when the cam gear springs uncoils and spins a bit. Just make sure you line up the timing marks and you will be fine.  Once you get all of the rear timing gear cover bolts removed, it can be rotated around the rear timing gear so the water pump can be removed.  It only needs to rotate a little to make way to slide out the water pump.

The other thing worth mentioning is that the crankshaft timing mark is on the top side of the crank.  See my picture below.

The best tip ever from another site was to use electrical ties to hold the timing belt on the cam gears during installation.  The rear cam gear and belt is nearly impossible to line up, so rotate it so you can see it, and then attach the electrical or zip tie around the cam gear and timing belt.  Once you have the other marks lined up simply cut the zip ties.