Brand New Mercury Mercruiser Alpha One Gen II Lower Driveshaft Assembly (1991-Current)

This is a brand new genuine Mercury Lower driveshaft assembly (also known as the lower gearcase or lower unit) for Mercruiser Alpha One Generation II sterndrives, compatible with models from 1991 to present (serial numbers 0D494570 & higher). It includes a 1-year manufacturer warranty for peace of mind.

Available Gear Ratios: Please select your required gear ratio below:

• 1.47:1 – Commonly used with higher HP V8 engines (e.g., 5.7L/350 and up, 220+ HP models)
• 1.62:1 – Commonly used with 4.3L V6 or lower HP V8 engines in standard applications
• 1.81:1 – Commonly used with some 4.3L V6 models, especially earlier Gen II or heavier boats
• 2.00:1 (or 1.94:1 equivalent) – Commonly used with 3.0L 4-cylinder engines (130-135 HP); note that 2.00:1 replaced 1.94:1 starting around 1998 for improved durability

Please note: This item is typically not stocked in-store and ships directly from the manufacturer for guaranteed freshness and quality.

Important Fitment Information: To ensure you receive the correct upper unit with the proper gear ratio and full compatibility, please provide your sterndrive serial number and engine details (HP, cylinders, model/year) from the transom bracket. We're here to help verify the exact match!

Special Note: The yoke/input shaft design changed with Gen II models starting at serial number 0D494570. This upper unit is specifically for Gen II and is not compatible with earlier Gen I ("R" style or pre-1991) without potential modifications.

If you have any questions, feel free to email us at jhawknz@gmail.com or call 615-691-1433. Our team is ready to assist with your purchase.

This upper driveshaft assembly comes complete and ready for installation, with no core charge required.

An optional 12-month extended warranty is available for an additional $540.

Welcome to OBR Parts and Marine Since 1982, OBR has been the industry leader in providing new and remanufactured outboard powerheads, gearcases, and sterndrive units. Marine parts dealers across the nation trust us for top-quality components, prompt same-day shipping, and expert technical support. We're committed to getting you back on the water quickly and reliably!