Small Engines (Lawn Mowers, etc.): STX 38 John Deere Kohler 12.5 command, crankcase breather, kohler command

Question
I changed the filter and oil toward the end of last mowing season in my Kohler Command 12.5 engine.  Shortly after that I noticed an oil leak, it got worse and worse until I changed main shaft seal.  Seemed to work fine until the second mowing and started leaking again.  What would cause this seal to go bad?  Wrong filter? Crankcase not vented properly?

Answer
Hello Larry:

From your Description it Sounds like the Crankcase Breather Requires Cleaning, the Head Gasket is Blown between the Cylinder and the Push Tube Galley (OHV Engines Only) or the Crankshaft has Gotten Bent and Not Allowing the Seal to Seat Properly. I Suggest you Remove the Crankcase Pulley/PTO and have Someone Turn the Engine (Spark Plug Out) while you Watch the Crankshaft Center Bolt Hole as the Engine Turns. If the Crankshaft Wobbles, then it is Bent and Not Allowing the Seal to Seat. If the Crankshaft is OK, then Remove the Crankcase Breather and Clean. You can View a Breakdown/IPL of the Engine and Mower at this Site Addy, http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.H... and Enter the Model Numbers and Click Find. Then Select the Sectional File. Then Select the Section of the Mower you Wish to View Online. If you Hit a Snag or this Does Not Correct the Problem,  I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Thanks.

Good Luck

Respectfully

John

PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Thanks.

Respectfully

John