Used Mark 30H Gear Case rebuilt Dec 2017. This gear case started as a very fine looking gear case. The exterior and interior of the housing is in excellent contion. Like we do with all of the gear cases we sell looking at the inside is alway done. The only suprise we found was the 16:21 gears looked to be in like new condition but we found the main gear to be missing half of one tooth. So not knowing where the piece of the gear went we decided to replace all of the bearings and seal, replace the gears with NOS 1:1 Mercury gears, install a new impeller. The prop shaft and drive shaft were in excellent shape as was the drive shaft pilot. To dress it up a little we installed a new cone nut over the existing bearing carrier.