DIY Outboard Lower Unit Rebuild Video

Embark on a comprehensive technical journey with this in-depth video tutorial demonstrating the complete disassembly and reassembly of a Mercury Verado outboard lower unit. This detailed guide focuses on the intricate process of changing the driveshaft from a 20-inch to a 25-inch configuration, a common modification for optimizing performance across various boat applications. The tutorial meticulously covers each critical step, beginning with the essential task of draining the gear lube, followed by the careful removal of the torpedo ring, spanner nut, and tab washer. Viewers will gain insight into the proper use of specialized tools, such as the job puller for carrier removal, and observe the precise steps involved in detaching the reverse gear and bearing, and subsequently replacing the carrier seals.

The video then transitions to the driveshaft removal process, highlighting the sequence of taking off the water pump and housing, driveshaft seal carrier, and finally the pinion nut. Emphasis is placed on the careful handling and counting of needle bearings before proceeding to the removal of the prop shaft, forward gear, and bearing assembly. The expert demonstration further breaks down the prop shaft components, including the cotter pin, nut, gear, clutch dog, spring, pin, and rod, providing a clear understanding of each part's function. The removal of the shift shaft and shift crank completes the initial disassembly phase. The reassembly portion of the tutorial is equally thorough, illustrating the installation of new bearings onto the replacement driveshaft, the careful reinsertion of the shift crank and shift shaft (with a new seal), and the precise reinstallation of the prop shaft assembly. Viewers will learn how to correctly reincorporate needle bearings using grease, and how to properly torque the pinion gear and driveshaft nut. The video culminates with the reinstallation of the bearing carrier, tab washer, spanner nut, and torpedo ring, concluding with vital steps like pressure checking the unit and refilling the gear case. This tutorial is an invaluable resource for marine mechanics and avid boat owners seeking to understand the internal mechanics of an outboard lower unit, ensuring proper maintenance and repair techniques.