Description
Volvo Penta DP-SM Lower Unit – OEM #3855907 | 1.78 Ratio | 17/29 Splines | Genuine OEM
Fits: Volvo DP-SM Outdrives, Ratio: 1.78, Splines: 17/29, OEM Part #: 3855907
This new OEM lower unit is designed specifically for Volvo Penta DP-SM outdrives, delivering powerful and efficient performance. It features a 1.78 gear ratio with a 17/29 spline configuration, offering seamless compatibility with your Volvo dual-prop system.
Built by Volvo Penta, this is a genuine OEM lower unit—not an aftermarket product. Precision-crafted to Volvo’s rigorous standards, it ensures superior durability and fit for your marine engine. This unit is ideal for replacing your worn or damaged lower gearcase.
Whether you’re restoring performance, improving reliability, or maintaining your investment, this OEM Volvo Penta DP-SM lower unit is the best solution on the market.
If you need help identifying the right Volvo-Penta DP parts, our experts are just a call away. We also have full diagrams and schematics including the Volvo Penta DP-SM parts diagram for your reference.
View our parts finder to find Volvo-Penta parts to verify this is a match or contact us using the buttons at the bottom of the page.
You can also use our parts finder to find other Volvo-Penta Boat Parts.
Looking to save money? Be sure to check out our remanufactured DPSM lowers, offering the same quality at a reduced price.
Features & Benefits:
- Fits: Volvo Penta DP-SM Outdrives
- Gear Ratio: 1.78
- Splines: 17/29
- OEM #: 3855907
- Brand New – Not Rebuilt or Aftermarket
- Built by Volvo-Penta, engineered for long-term performance
- 1-Year Warranty from US Boatworks
- Compatible with official Volvo Penta DP outdrive parts diagrams
- Optimized for high-performance dual-prop systems
- Ideal for those looking for a new lower unit on an outboard motor or full DP drive restoration
Pricing
Total Price: $9,000
Less $500 Core rebate Final Price: $8,500
Product Finish:
- Factory-new OEM finish direct from Volvo Penta
- Sealed and ready for installation
- Built for both saltwater and freshwater conditions
Core Rebate Information
- Return your old core, get up to $500 back
- Rebate amount will vary based on the condition of your core
- ♻️ Recycle your core- keep boat parts out of the landfill
Useful Resources
- 🔍 How to find your Boat Engine serial number?
- Still deciding? Watch our YouTube video How to avoid common lower unit replacement mistakes
- To help extend the life of your gearcase, check out our Boat Maintenance Checklist
🛥️ Please have your Engine Serial # ready when you contact us if possible. 🛥️



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