Genuine Bentley / Rolls-Royce Starter Motor Driving Shaft Gear - DB986 (1946-1955)

Genuine OEM Starter Motor Driving Shaft Gear (DB986). This critical internal electrical component is designed for the Lucas-style starter motors found in the Bentley MkVI, R-Type, and Rolls-Royce Silver Dawn/Wraith. Precision-cut from hardened steel, this gear ensures reliable engagement between the starter armature and the drive assembly, restoring factory-standard starting performance to your heritage motorcar.

Restore the reliability of your classic's ignition system with the Genuine Starter Motor Driving Shaft Gear (DB986).

Often overlooked during starter rebuilds, the driving shaft gear is subject to intense frictional wear and mechanical stress during every start cycle. A worn gear can lead to "slipping" during engagement or excessive noise. This genuine replacement is manufactured to the original 1940s-50s metallurgical specifications, ensuring perfect mesh compatibility with the DB987 idler gears and preventing premature wear on the starter armature.

Topical Authority Specs:

• OEM Part Number: DB986.
• Material: Case-Hardened High-Grade Steel.
• Component Type: Internal Starter Motor Gear.
• Compatibility: Bentley Mark VI, Bentley R-Type, Rolls-Royce Silver Dawn, Rolls-Royce Silver Wraith.
• Period Correct: 1946–1955 Production Years.

The Heritage Advantage: Unlike "universal" modern reproductions, the DB986 gear is machined with the exact tooth profile required for vintage Lucas starter units. This prevents "binding" and ensures that the high-torque load of the 4.25L and 4.5L engines is handled without straining the electrical system.

 

Tech Tip:

When installing the DB986 Driving Shaft Gear, ensure you thoroughly clean the armature shaft and inspect the DB857 Bearing Pins for any signs of ovality. For a 12-hour professional restoration result, apply a high-temperature, non-conductive dielectric grease to the gear teeth to reduce friction without interfering with the starter's electrical path.