Yanmar SD20 | SD30 | SD31 Sail Drive Unit Service Workshop Manual

Workshop Service and Repair Manual for the Yanmar SD20, SD30 & SD31 Sail Drive Unit, an absolute gem for anyone working on these units. This full workshop manual covers every component, service and repair procedure in full Yanmar factory specification with clear step by step technical drawings for the Yanmar SD20, SD30 & SD31 Sail Drive Units with torque setting values throughout each chapter, this is the most comprehensive service manual available as used by boatyards and independent marine engineers the world over.

Below is a list of the items covered within this manual.

Chapter 1 General
Specification
Sectional View & Names Of Parts
Criteria For Replacing Parts
Disassembly And Reassembly Tool
Notes On Disassembly, Inspection And Reassembly

Chapter 2 Disassembly
Disassembling The Upper Gear Case
Disassembling The Lower Gear Case

Chapter 3 Reassembly
Reassembling The Propeller Shaft Assembly
Reassembling The Pinion Shaft Assembly (Input Shaft)
Reassembling The Upper And Lower Gear Cases
Lubrication
Attaching The Folding Propeller

Chapter 4 Shim Adjustment (Gear Backlash Adjustment)
Location Of Adjustment Shims
Replacements Requiring Shim Adjustments
Adjusting The Upper Pinion Gap
Adjusting The Upper Gear Backlash
Adjusting The Lower Gear Backlash

Chapter 5 Bearing & Oil Seal Replacement
Replacing The Upper Gear & Bearing
Replacing The Clutch Shaft, Dog Clutch & Needle Bearings
Replacing The Driving Shaft Bearing
Replacing The Propeller Shaft Bearing
Replacing The Propeller Shaft Oil Seal
Replacing The Lower Gear Case Needle Bearings

Chapter 6 Tightening Torques For Nuts And Bolts
Tightening Torques For Nuts And Bolts

Chapter 7 Electrical Wiring
Electrical Wiring
Checking Rubber Seal Switch Operation
Electrical Wiring Diagram (A-type Instrument Panel)
Electrical Wiring Diagram (8-type Instrument Panel)

Chapter 8 Modifying,
The Long-reach Unit (Optional Parts)
General
Modification Method