I would send a copy of all the posts here directly to Canadian Tire at this address:
PO Box 2000, Station Main
Welland, ON
L3B 5S3
And to TroyBilt at this address:
P.O. Box 361131
Cleveland, Ohio 44136
Explain to each of them that you feel that you are getting the run-a-round, because no one will help you. Include copies of the receipts and work orders from the service shop. It is my opinion that HydroGear ships their drives dry for safety reasons and it is the responsibility of the equipment manufacturers to fill and test them. I know that this is going to be a pain in the butt to do, and will take time, but just giving you my opinion. I have worked with many of the manufacturers of both equipment and engines and 95% of the time they are very willing to help. If they know that you are trying to get help on forums like this, they probably don't want the bad press. If Canadian Tire sent you to this service dealership, I am wondering why they are not doing more to resolve this problem, if for no other reason than to get your business in the future.
Sorry, that's the only suggestion I can give you at this time.