Upgrade to the Upgraded Flywheel

The Viking factory reported some incidents of ring gear slippage on the new flywheel assembly that I recently upgraded to.  The recommended remedy was to remove the unit and separate the ring gear from the flywheel and make some changes.

So, off to drain and then remove the radiator, then the PSRU and finally the flywheel/ring gear assembly.  The remedy begins by bonding the ring gear to the flywheel with green Loctite.  After some research, I resolved to use Loctite 620 which is the most viscous and highest shear strength of the green Loctite family for this application.  But alas, I'm getting ahead of myself.

The ring gear had to be separated from the flywheel first and then the two components cleaned thoroughly with acetone prior to bonding with Loctite.  The first two photos below show the nice bead of Loctite that resulted from dropping the heat soaked (to 350 deg F) ring gear down onto the flywheel.

The final step of the process involved the replacement of the smaller washers with some AN970-3 washers that had a larger outside diameter for greater surface area contact.  I also used some red Loctite on the nuts, which are also secured with lock washers.  See below.

Now it was time to bolt the flywheel back onto the engine, after scrubbing the 6 bolt's threads clear of the previously used blue Loctite.  As usual the bolts were torqued back down to 80 foot pounds per Viking and secured with blue Loctite again.

I like to refer to the next shot as the "sacred geometry".  The rubber isolators have to be oriented as shown with the factory sketch ON the flywheel, below.

The next major step of the process involves aligning the PSRU studs of the spider gear and driveshaft to the rubber isolators and the crack bushing.  The business side of the PSRU as it is readied for installation.

PSRU in place.

Oil line from the engine galley plumbed into the top of the PSRU.

Then the gearbox temp probe is installed too.

The last major step in the process is to plumb the gearbox oil discharge line from the former location of the siteglass back to the oil tank.

It takes careful orientation of two elbows at the site glass location to negotiate the path around the coolant tube as shown below.  After running out of room with the cowling in my original configuration, I had to re-route the oil line aft of the coolant tube.  It worked out okay, but I was really sweating it to get to this perfect arrangement.  Four pictures to show the various angles of this tightly configured area.

It looks like I'm back to where I started again....hopefully that is the final install of the upgraded flywheel.