Replacing the timing belt on a 98-05 (B5) V6 VW Passat is not easy.
VW says to replace it at 105K, Bentley recommends 70K.
If the belt snaps, your engine will break, as it's an interference design.
I will never buy another car that uses a belt, the 06-current (B6) VR6 VW Passat uses a proper timing chain that doesn't need replacing.
Here is how one person replaced the belt.
The following are notes on my experience following those directions.
Date: Tue, 18 Jul 2006 12:47:47 -0400
To: foster_cat at yahoo dot com
From: Eben <foster_catatyahoodotcom at netdevice dot com>
Subject: Passat page
The instructional on replacing the V6's timing belt helped me greatly, thanks.
I have several comments;
In step 18 there was a clip that held the hood release cable to the lock carrier and radiator section about half way from the lock to the right fender, I had to unclip that.
In step 30 I could only swing the lock carrier radiator section outward 45 degrees because of the AC lines that I didn't want to disconnect.
In step 42 I had to feel with my pinky for the indentation.
There was no way I could see in, even with a mirror.
Possibly it's my 46 year old eyesight though.
I screwed in VW tool 3242 and used the 24mm socket to slightly rock the crankshaft back and forth so that the tool was able to fully seat in the indentation.
In step 45, the power steering pump pulley needs to be removed if one is replacing the timing belt tensioner.
Torque is 25 Nm/18 ft-lb on the three 8mm Allen Socket bolts.
In step 50 or 52 I found that I had to use VW tool 3391 as a lever arm to get the same tension in the upper belt section between the camshaft sprockets that the old belt had; about a half inch play either way on the left of the water pump roller, and slightly less on the right.
In doing so I was able to have the tool line up exactly straight across the camshaft sprockets.
There was no way I could have muscled the belt over the second camshaft sprocket without it.
They should call it a combination alignment and lever arm tool instead.
I started by threading the left side of the belt around the crank sprocket, over the tensioner, around the left camshaft sprocket, and under the water pump roller.
Then I threaded the right side of the belt over the idler roller, then loosely near the right camshaft sprocket.
I then placed the tool in position.
Then I slipped the right end of the tool off of the right camshaft sprocket and rotated the tool downward while leaving it engaged in the left camshaft sprocket holes.
This was enough to cause the belt to move rightward enough so that I could slip it over the right camshaft sprocket, and after releasing the tension, the alignment of the camshaft sprockets was undisturbed.
Releasing the tension on the tensioner then took up the slack in the belt section lower than the camshaft sprockets.
Step 62 needs to go between 53 and 54, as the viscous fan pulley fits under the lower, middle and driver side timing belt covers.
Add to step 64 to reinstall the power steering pump pulley if it was removed in step 45.