Re: little oily
it is a Mercruiser IL6.
The wheel is also called fly wheel. It is next to the lower wheel that drives the camshaft.
Ok...
Well the "flywheel" is a steel disk that also has gear "teeth" on it. It's located in the rear of the engine and is completely enclosed in the "Flywheel Housing".
The "wheel" you refer to is most likely the vibration DAMPER.
The vibration damper is located in the FRONT of the engine. It is connected to the crankshaft and has an oil SEAL behind it in the timing cover....under which the timing GEARS are located which as you indicated turn the camshaft.
If you have an oil leak in that area you would have to remove the vibration damper (using a "puller") and the timing cover to replace the seal. you might be able to replace the seal without pulling the (rather thin metal) cover, but you run the risk of warping the cover. That would probably cause a leak even with a new seal.
A leak in that area can also be a leak in the timing cover gasket or the timing cover itself may have corroded and is leaking. You'd have to replace it too if it is corroded enough to leak
The following link shows the timing cover seal/gasket kit and lower in the page a picture of a timing cover for a 6cyl
http://bpi.ebasicpower.com/pc/MEL2528S/MER6U/Timing+Gear+Set+GM+Inline+4+&+6+Cylinder
Regards,
Rick
