21255887 Gear Set | Genuine Volvo Penta Part

🔧 Product Description

Genuine matched gear set used in the Volvo Penta DPH-A sterndrive. The gears are supplied as a matched set to maintain correct tooth contact and the specified 1.76 drive ratio.

🚤 Compatibility

• Engine Family: D, DPH
• HP Range: 225-370 HP

Full model list at the end of this description.

⚙️ Key Features

• Genuine Volvo Penta matched gear set
• DPH-A sterndrive application
• 1.76:1 ratio
• Precision-matched gear tooth contact
• Must be installed with correct shimming and bearing preload

🔌 Function

The gear set transfers engine power through the upper drive while reducing rotational speed to the specified sterndrive ratio.

⚠️ Common Signs of Failure

• Gear whine or knocking
• Chipped teeth
• Drive vibration
• Loss of propulsion
• Water-contaminated oil accelerating gear damage

🛠️ Service Notes

• Gear sets are supplied as a matched set and must be fitted complete — never run a new gear against a used mate, and keep the set together as it was delivered
• Setting up requires the shimming, backlash and tooth contact pattern checks in the workshop manual for your engine and drive, together with the proper measuring and pressing tools; this is not a fit-and-hope job
• Establish why the old set failed before assembly — debris, a collapsed bearing or oil starvation will destroy the new gears just as quickly
• Renew the bearings, seals and locking hardware at the same time, and flush the housing thoroughly so no metal debris is left in it
• Fill with the oil specified for your drive, then check the oil early in service for signs of abnormal bedding-in debris

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 21255887 → Supersedes 3862370

OEM / Related Numbers

• 3862370 earlier number superseded by this part

Aftermarket / Verified Equivalents

• Ratio identification: 1.76R

📦 Condition

• Genuine Volvo Penta part
• Brand new
• Supplied in original or equivalent packaging

🔎 Full Model Compatibility

Typically suits:

• Volvo Penta D6-370A-C, D6-330A-D, D6-330A-C, D6-370A-D, D6-330A-E, D6-370A-E, D6-280I-D, D6-310I-D, D6-330I-C, D6-330I-D, D6-280A-C, D6-310A-C, D6-280A-D, D6-310A-D, D6-280A-E, D6-310A-E, D6-280I-C, D6-310I-C
• Volvo Penta D4-260A-C, D4-260A-D, D4-260A-E, D4-300A-C, D4-300A-D, D4-300A-E, D4-225I-C, D4-225I-D, D4-225A-C, D4-225A-D, D4-225A-E
• Volvo Penta DPH-A