Rear Main Seal Oil Leak

I have a TO-35 that has an oil leak. Project started off replacing the flywheel, but mechanic suggested replacing rear main seal. Sounded like a good idea? Problem is where the rear main seal sits with retainer, there are two holes where oil is leaking from. We don”t know what the two holes are. Or what went there?

I don’t recall what those two holes are for but I do know when the rear main seal is correctly installed with a gasket under the flange and copper sealing washers under the heads of the two lower bolts that are installed from the inside of the crankcase, there should be no leaks. You have to be very careful when installing the flange and seal assembly so you don’t damage the seal surface. Coat the surfaces with gasket sealer before installing a new gasket between the seal flange and the block. There is a half moon flange that goes over the top of the seal flange where the three upper bolts are installed from the clutch side. Regular flat washers are installed under the heads of these three bolts. The flange has two square nuts welded to it for the lower two bolts that are installed with the copper sealing washers from the inside of the crankcase. Ferguson originally serviced the seal and flange as a complete assembly and as a seal only that was installed in the old flange. The seal only was usually the one that was included in the engine overhaul gasket kits. You have to be very careful in installing a new seal in an old flange in order to get it seated squarely. Installing a seal and flange assembly was usually done to avoid the problems associated with replacing the seal only. Sadly, I do not believe the seal and flange assemblies are available any longer. The assembly was sold as part number 1750216M92. The gasket under the seal is part number 1750112M1. The copper washers were available under two part numbers, 1002044M1 and 1751636M1