21550240 Lower Gear | Genuine Volvo Penta Part

🔧 Product Description

A complete lower-gear assembly for Volvo Penta DPR-A propulsion drives using the catalogue-designated 1.4 reduction ratio.

🚤 Compatibility

Typically suits:

• Volvo Penta D6-370A-C
• Volvo Penta D4-300A-C
• Volvo Penta D4-300A-D
• Volvo Penta D4-300A-E
• Volvo Penta D6-370A-D
• Volvo Penta D6-370A-E
• Volvo Penta D6-400A-E
• Volvo Penta DPR-A
• Volvo Penta DPR-C
• Volvo Penta DPR-D
• Volvo Penta DPR-B

• Engine Family: D, DPR
• HP Range: 300-400 HP

⚙️ Key Features

• Complete lower-gear unit
• Catalogue ratio designation: 1.4
• Matched gears, shafts and bearings
• Counter-rotating propeller-drive construction
• Requires drive-specific setup and oil specification

🔌 Function

The lower gear changes the direction of drive and transfers power from the vertical shaft to the counter-rotating propeller shafts.

⚠️ Common Signs of Failure

• Abnormal gear noise
• Metal debris in the lubricant
• Water-contaminated drive oil
• Propeller-shaft play
• Drive overheating
• Loss of propulsion

🛠️ Service Notes

• Lower gears are supplied and worked on as a matched set — do not mix a new gear with used mating gears, and keep matched bearing pairs together
• Shim values must be re-established whenever gears, bearings or housings are changed; set tooth backlash and check the tooth contact pattern against the specification for your drive rather than reusing the old shim stack blind
• This work needs the correct Volvo Penta special tools and measuring gear; without them the gear set cannot be set up correctly and will not last
• Work clean, inspect the housing bores and bearing seats, and renew the seals and O-rings that are disturbed
• Fill with the specified lubricant to the correct level, then run the drive gently under light load before working it hard, and check the lubricant for metal afterwards

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 21550240 → Supersedes 3862821 → Supersedes 3801131

OEM / Related Numbers

• 3862821 earlier number superseded by this part
• 3801131 earlier number superseded by this part

📦 Condition

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