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Add to CartThe SEI SE218 is an aftermarket replacement lower unit for compatible Mercury 3.0L counter-rotation outboards. These stub-shaft versions are available in 1.62:1 and 1.75:1 gear ratios for applications requiring a separate Mercury upper driveshaft.
A compatible Mercury upper driveshaft is required. Do not order this unit unless you already have the correct upper driveshaft in hand.
This item is subject to a 20% restocking fee.
Year, serial number, and horsepower are required to process your order. Please contact us with this information after placing your order. Processing will be delayed until this information is received.
SEI lists the SE218 family for most Mercury 3.0L lower-unit applications with serial numbers 1B504989 and below. Confirm your serial number, existing gear ratio, rotation, and driveshaft configuration before ordering.
Not a replacement for Torque Master, Torque Master 2, or Sport Master gearcases. For counter-rotation applications only.
For applications with an 8-spline driveshaft, SEI specifies the stub-shaft unit paired with the appropriate Mercury upper driveshaft:
SEI states that the 30" upper driveshaft is no longer available from the OE manufacturer. Confirm that you have a suitable shaft before purchasing.
The supplied water tube coupling suits serial numbers 0G438000 and higher. Earlier applications require reuse of the correct existing coupling or SEI part number 96-116-12K.
California Residents: 
WARNING
Cancer and Reproductive Harm -
P65Warnings.ca.gov
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