A few post back I posted,
"In the past two weeks I have burned two of those fans and I have had to learn how they work. The unsealed bearing was original and will last a lifetime if properly maintained. It uses centrifugal force to keep the oil in the hub with a pump at the north end to circulate the oil through the bearing. If the oil gets too low, the pump can't pick it up. The bearing is rather simple being just a shaft through a casting. You can't overfill since too much oil will simply flow out the unsealed end when the engine is not running. I would use somewhere between 45 and 90 W and fill till it runs out the south end. I did install one of the new sealed bearing types. Personally I do not believe they are as good as the originals."
The thing I left out was a discussion of the grease or gasket seals. There are two (2) gaskets at the front end of the bearing. One is behind a cover plate just behind the fan blades. The other is behind the bearing casting between the casting and the fan pulley. These gaskets may be available but I was not able to find any so I had to fab them from flat stock. Not hard to make but one is needed at both places. I used the front plate to trace out the outside circle and the 8 screw locations and simply cut it out and punched the holes using a hole punch. Scribing an inside circle I cut the inside hole ending with a circular gasket with the 8 screw holes. If your bearing begins to leak oil at one of these two places, replacing the gaskets could save the bearing.
"In the past two weeks I have burned two of those fans and I have had to learn how they work. The unsealed bearing was original and will last a lifetime if properly maintained. It uses centrifugal force to keep the oil in the hub with a pump at the north end to circulate the oil through the bearing. If the oil gets too low, the pump can't pick it up. The bearing is rather simple being just a shaft through a casting. You can't overfill since too much oil will simply flow out the unsealed end when the engine is not running. I would use somewhere between 45 and 90 W and fill till it runs out the south end. I did install one of the new sealed bearing types. Personally I do not believe they are as good as the originals."
The thing I left out was a discussion of the grease or gasket seals. There are two (2) gaskets at the front end of the bearing. One is behind a cover plate just behind the fan blades. The other is behind the bearing casting between the casting and the fan pulley. These gaskets may be available but I was not able to find any so I had to fab them from flat stock. Not hard to make but one is needed at both places. I used the front plate to trace out the outside circle and the 8 screw locations and simply cut it out and punched the holes using a hole punch. Scribing an inside circle I cut the inside hole ending with a circular gasket with the 8 screw holes. If your bearing begins to leak oil at one of these two places, replacing the gaskets could save the bearing.
