The crank seal on a Kubota will not last forever. Daily duties, such as mowing and digging, strain the engine crankshaft, wearing out the seal, and ultimately, a bad seal will allow oil to leak from the engine. However, you can replace this seal, regardless of your level of experience, in four to eight hours.
Remove the belt pulley and harmonic balancer using a pulley removal tool, which can be purchased at most automobile parts stores. Two hooks are attached to a central screw shaft. The hooks are connected behind the pulley, and the central screw shaft is tightened to remove the pulley and harmonic balancer from the crank shaft.
Inspect the shaft to see whether the shaft key remains in place. The shaft key is inserted into a groove on the shaft and used to hold the pulley and harmonic balancer in place.
Remove the seal from around the shaft using a screwdriver. Be careful not to damage the metal housing or the crank shaft. Pry the seal loose from the shaft. You may need to tap the screwdriver into the seal metal. If so, hammer with caution.
Clean the housing in which the old seal sat. Wet a cotton rag with acetone, and wipe the metal clean. If any seal debris remains, scrape it free with a one-inch putty knife. After all seal rubber has been removed successfully, wipe the housing once again to clean dirt and grime from the shaft housing.
Grease the shaft housing and the outer edge of the new seal with synthetic grease (white grease). Wear rubber gloves prior to handling the grease. Scoop the grease into your fingers and place it onto the metal surfaces, applying it liberally.
Place the seal onto the crank shaft with the correct side facing out. The seal will have a mark indicating the correct direction of installation. Slide the seal as far into the housing as possible. Gently tap it further in place with a rubber hammer. Replace the harmonic balancer and belt pulleys.