They are replaceable but may not need to be depending on tilt problem. I had water in clutch housing last year so I removed cover and found clutch pack looked O.K. so I just cleaned it, replaced gear shaft seal, and housing plate O ring and gasket, refilled housing (type C lube) and it works good. If you replace gear seal the transom quadrant needs to be removed to get access to seal. The OD needs to be propped up with stick or something so you maintain position. Wasn't that big of a job except for getting the three bolts backed out of the quadrant plate.