04-05 Passats come with a BHW engine with a chain driven balance shaft. These chains are chronically noisey and fail. Some cars have failed and had the chain & sprockets replaced, only to fail again. The fix for this is upgrading the Chain driven Balance Module to a gear driven Balance module. This is a large job that includes setting the “lock-carrier” to the service position, removing the timing belt, removing the sub frame and oil pan.  This job rates at about 8.3 hours. This should be done at the same time as a timing belt, even if you’re not having the noise. This is because if the noise develops after a timing belt job, you would end up paying the same labor again for the timing belt work.



Here are the new tools I got to do this work. Other tools are necessary as well, like crank counter hold tool, VCDS, XZN sockets, Torx sockets, Allens, etc. But I already had those.


To set the lock carrier in the service position you must strip the front end till it’s naked. I choose to not remove the lock carrier to avoid loosing expensive trans fluid G052162A2 ($15/quart), antifreeze G12 ($12/ liter) and Freon. This saves money.


You pull the timing cover and lock it down.  Note special tools.


To get the oil pan off subframe removal is required. Volkswagen  offers a special tool to line the subframe back up.


Here is the chain driven balance module in all its glory.


Here’s the chain drive. The TB pulley that is on the crank is on with massive torque. Removing takes a “counter hold” tool which is also required for reassembly.


Pulling the crank sprocket takes a special tool that looks like this.


Here is the gear driven balance module.


Here’s the new balance module installed and torqued down, with the balance lock in position.


Balance Module Delete

Some real smart techs developed the Balance module upgrade and we can eliminate the chain driven balance module and put in a gear driven balance module.  This is a nice fix but its fairly pricey.  Later some other smart techs developed a way to remove the balance module all together.  This eliminates the expensive part replacement and saves bunches.  Other Tdi’s of similar years with almost the exact same engine dont have a balance module at all.  We’ve removed the Balance Module on a couple now and it seems to be a good solution.  It is not as smooth and nice as a gear driven balance module but the price makes it desireable if you can live with slight vibration.  These cars seem to vibrate a bit anyway expecially with a worn chain so you might not even notice unless your really attentive.

All the work to do Balance Module Delete is exact the same as the Balance module upgrade so the labor cost is the same.  You save on parts by doing the delete.


Here’s what it looks like in the pan with the balance module removed.

BM Delete



If your considering this service please contact us and we can help you.  —–>    Contact us here……..