- New
Volvo Penta DP-SM Lower Unit Sterndrive
$3,299.00
Brand New Volvo Penta DP-SM Lower Unit Sterndrive. Ready to Install !!
Brand New Volvo Penta DP-SM Lower Unit Sterndrive. Ready to Install !!
Volvo Penta DP-SM Lower Unit Sterndrive
Part Name: Lower Gear Housing Assembly
Model Series: DP-SM (Duoprop Sterndrive, Mechanical Shift)
Gear Ratio: 1.95:1
Propeller Type: Duoprop (Twin Counter-Rotating Propellers). This unit uses F-Series propellers (Front and Rear props rotate in opposite directions)
Compatibility & Application
This lower unit is part of the Volvo Penta "290" series family. It is crucial to match the gear ratio to your specific engine and upper drive unit.
Common Engine Matches (1.95 Ratio):
The 1.95 ratio is typically found on 4-cylinder gasoline engines. It is most commonly paired with:
> AQ171 (4-cylinder, 171 cu in)
> AQ131 (4-cylinder, 131 cu in)
> Some variations of the 3.0L/4-cylinder engines depending on the year and transom shield.
Drive Compatibility
This unit connects to an Upper Drive designated as DP-SM or 290 SP-A/DP-A type drives with mechanical shift.
Important: You cannot mix gear ratios. If your current upper drive housing is stamped with a ratio other than 1.95, this lower unit will not be compatible without changing the upper gears as well.
Technical Details
Shift Mechanism: This is a Mechanical Shift unit. It uses a shift cable that runs through the transom shield and the drive to engage forward/reverse. It does not have the electronic shift actuator found on newer DPS or DPH drives.
Cone Clutch: Like most Volvo Penta 290 series drives, this utilizes a "Cone Clutch" mechanism for shifting. It is known for being durable but can be stiff to shift if the cable is worn or if the cone clutch surfaces become sticky.
Water Pump: The water pump (impeller) is located inside the upper drive unit, not the lower unit. Replacing this lower unit does not require touching the impeller, though it is good practice to service the upper pump when working on the drive.
Parts & Replacement Status
OEM Availability: The part number 3860765 is generally considered obsolete or "No Longer Available" directly from Volvo Penta as a brand-new complete assembly.
Aftermarket Options: Due to the age of the DP-SM drives, you will often find this lower unit sold as an aftermarket replacement or a remanufactured unit.
Common Issues to Check:
Chipped Skeg: Check the bottom fin (skeg) for damage from grounding.
Prop Shaft Play: Grab the propeller shafts and check for excessive vertical or horizontal play, which indicates worn bearings.
Oil Condition: The gear oil should be golden/clear. If it is milky (water intrusion) or metallic (gear damage), the unit needs to be pressure tested before installation.
Installation Tips
If you are replacing this unit yourself:
Gasket/O-Ring: Ensure you have a fresh gasket and O-ring set for the junction between the lower unit and the upper drive housing. This seal prevents water from entering the upper unit.
Shift Cable Alignment: Before tightening the lower unit to the upper, ensure the shift cable is properly engaged in the shift fork mechanism.
Oil: Fill the lower unit with Volvo Penta High Performance Gear Oil (or a high-quality GL-5 75W-90 synthetic specified for marine sterndrives) through the bottom drain plug until it comes out the side vent plug.
Summary: This is the lower half of a twin-prop sterndrive designed primarily for 4-cylinder VolvPenta engines from the late 1980s to mid-1990s. If you are purchasing a replacement, verify that your upper drive housing matches the 1.95 ratio stamp.
No customer reviews for the moment.