Shade tree mechanic 1810 blues

[Grand Pops 1810]

Pulled the PTO off the front (?) of my Magnum 18 today to replace my bad oil seal. What an oily greasy mess! I had already ordered my front seal and was ready to go. Then I learn that the PTO is on what is considered the "rear" of the engine, and the flywheel is on the "front" of the engine (?!?)... So I need a rear seal to install on the front of the engine. Apparently Cub installed the Magnum 18 backwards in the frame compared to the intended Kohler design?? Once the PTO is out of the way, I see that the bad oil seal is loose in its bore, you can move it easily with your finger. That would cause an oil leak!! Reading online, this is a common problem with this engine, and the seal needs to be glued in place. Glad I found that out now! And the epoxy (?) covering on the PTO electro-magnet is swelling and cracking with chips falling out. It still works, so I'm guessing I can just clean it good and seal the cracks with silicone? Or is it time for a new PTO magnet while I'm in there?

[J-Mech]

Yes, the PTO is the "rear" of the motor. If you looked up your own parts you should have noticed which end was labeled what.

The seal does not need "glued in". Just dry everything and install a new seal. Don't use two, and DO NOT use silicone on the outside of the seal. If you do it definitely won't hold. Install dry, plain and simple.

You can use silicone on the coil.... epoxy is better.

[dale c.]

the pto might work for a long time yet ,and it may not .I recommend using it till it quits ,you might want to get a new one so you have it on hand ...the seals do come loose in the block I always put a little liquid Teflon [lightly]in the bore before I bump the seal in

[zippy1]

Just did the rear seal in my 1872, and my field coil was also cracked, but that's okay because it works and you don't want to buy one until you have to. $200
Did you not look up the part # by the picture? You can see the seal is behind the PTO....

[bill682]

There were two different threads started by you that stated you needed the rear seal.

http://www.onlycubcadets.net/forum/s...ad.php?t=37951

http://www.onlycubcadets.net/forum/s...ad.php?t=38095

[Grand Pops 1810]

Yesterday was the first time I had the PTO off to see the bad seal first hand. The seal was very loose in its bore, you could rotate it with your finger! As loose as it was, it had to be leaking lots of oil from the metal to metal mating surface, rather than from the rubber seal to shaft surface. I ordered the incorrect front seal online before disassembly, and read down the crankcase list until I found front seal. You are correct, if I had studied the exploded diagram more carefully instead of scrolling down the list, I should have seen that the rear seal was located behind the PTO. Live and learn. I'll always remember now that a Magnum installed in a Cub is backwards. I will try and reseal the electric clutch and get some more use out of it. It will be nice to mow with a quality machine again soon after using a hand-me-down Wal-mart mower so far this year.

[J-Mech]

Originally Posted by Grand Pops 1810

I'll always remember now that a Magnum installed in a Cub is backwards.

ALL the Cubs engines are in "backwards", not just the Mag's.

[Grand Pops 1810]

Okay, that's very interesting and good information that I did not know as a relative Cub newbie! Thanks!

[Sam Mac]

Not just Cubs, JD's like the 317, 318, Kubota BX's this is very common

[Grand Pops 1810]

This is interesting. So is the flywheel typically considered the front of the engine and PTO rear? Or do some (non-Kohler) brands of engine consider the flywheel at the rear?