OBR Mercury 115 HP four-stroke lower unit side profile
ME-G4-06-N Mercury 115 lower unit with 20-inch shaft
ME-G4-06A-N Mercury 115 lower unit with 25-inch shaft
Mercury four-stroke gearcase driveshaft and mounting surface
Mercury lower-unit shaft-length measurement guide
OBR Mercury 115 HP four-stroke lower unit side profile
ME-G4-06-N Mercury 115 lower unit with 20-inch shaft
ME-G4-06A-N Mercury 115 lower unit with 25-inch shaft
Mercury four-stroke gearcase driveshaft and mounting surface
Mercury lower-unit shaft-length measurement guide

OBR Mercury 4-Stroke Lower Unit | 115 HP 2001–2006 & 75–115 HP 2007–2014

$2,829.00
$3,132.42
$2,829.00
SKU: ME-G4-06-N
Product type: Lower Unit
Please hurry! Only 100 left in stock
Subtotal: $2,829.00

Required for fitment review to confirm compatibility.

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OBR New and Remanufactured Options
20-Inch L and 25-Inch XL Configurations
Engine Serial Number Required
24-Month Supplier Warranty; Terms Apply
Application Reviewed Before Shipment
OBR Mercury 115 HP four-stroke lower unit side profile

OBR Mercury 4-Stroke Lower Unit | 115 HP 2001–2006 & 75–115 HP 2007–2014

$3,132.42 $2,829.00
OBR Mercury 115 HP four-stroke lower unit side profile
ME-G4-06-N Mercury 115 lower unit with 20-inch shaft
ME-G4-06A-N Mercury 115 lower unit with 25-inch shaft
Mercury four-stroke gearcase driveshaft and mounting surface
Mercury lower-unit shaft-length measurement guide

OBR Mercury 4-Stroke Lower Unit | 115 HP 2001–2006 & 75–115 HP 2007–2014

$3,132.42 $2,829.00
Product Type: New Lower Unit
HP/Shaft/Years/Ratio: 115 HP / L Shaft / 2001-2003

    The OBR Mercury 115 HP four-stroke lower unit is available as a new or remanufactured replacement gearcase for selected four-cylinder Mercury outboards. The available configurations cover 115 HP applications from 2001–2006 and selected 75 HP, 90 HP, and 115 HP four-stroke applications from 2007–2014.

    Six application and shaft combinations are available in both conditions. The 2001–2003 group uses separate 20-inch L and 25-inch XL SKUs and is identified by the verified serial range 0T178500 through 0T800999. Separate OBR part numbers apply to the 2004–2006 and 2007–2014 generations.

    Horsepower alone cannot confirm fitment. The engine serial number, model year, four-stroke configuration, and shaft length must match the selected SKU.

    • 4-Stroke Optimized: Tailored to the power curves of the 2001–2003 115 HP 4-cylinder series.

    • Rugged Performance: Built with high-strength alloys to ensure maximum longevity in both fresh and saltwater.

    • Direct Fitment: Precision-machined to OEM standards for a seamless installation without modifications.

    • Manufacturer / Brand: OBR Parts
    • Compatible engine make: Mercury
    • Product type: Replacement lower unit / gearcase
    • Engine type: Four-cylinder four-stroke
    • Horsepower: 115 HP for 2001–2006
    • Later applications: Selected 75/90/115 HP for 2007–2014
    • Condition options: New and remanufactured
    • Shaft options: 20-inch L and 25-inch XL
    • 2001–2003 serial range: 0T178500–0T800999
    • 2001–2003 configuration: Short shift-rod generation
    • Standard gear ratio for verified 115 HP family: 2.07:1
    • Rotation: Standard configuration; verify by serial
    • Number of variants: 12
    • New SKUs: ME-G4-06-N, ME-G4-06A-N, ME-G4-07-N, ME-G4-07A-N, ME-G4-07B-N, ME-G4-07C-N
    • Remanufactured SKUs: ME-G4-06-R, ME-G4-06A-R, ME-G4-07-R, ME-G4-07A-R, ME-G4-07B-R, ME-G4-07C-R
    • Supplier warranty: 24 months; terms apply
    • Engine serial number: Required before shipment
    • Select ME-G4-06-N or ME-G4-06-R for a verified 2001–2003 Mercury 115 HP four-cylinder four-stroke using a 20-inch L shaft.
    • Select ME-G4-06A-N or ME-G4-06A-R for the corresponding 25-inch XL application.
    • The verified 2001–2003 serial range is 0T178500 through 0T800999.
    • Select ME-G4-07-N/R or ME-G4-07A-N/R only for applicable 2004–2006 Mercury 115 HP four-stroke engines.
    • Select ME-G4-07B-N/R or ME-G4-07C-N/R only for selected 2007–2014 Mercury 75 HP, 90 HP or 115 HP four-stroke applications.
    • Confirm the engine serial number, horsepower, model year, four-stroke configuration, shaft length and existing gearcase configuration.
    • Contact Mariners Warehouse if the serial label is missing or unreadable.
    • Do not choose this lower unit using horsepower alone.
    • The 2001–2003 and 2004–2006 groups use different OBR part numbers and shift-rod configurations.
    • A 20-inch L gearcase cannot replace a 25-inch XL gearcase without the correct conversion components and supplier approval.
    • Do not use these SKUs for Mercury two-stroke carbureted engines.
    • Do not use them for Optimax or other DFI applications.
    • Do not use them for Command Thrust, Pro XS or counter-rotation applications unless the exact SKU has been confirmed.
    • Confirm the gear ratio for every 2007–2014 75/90/115 HP order before release.
    • Submit the complete Mercury engine serial number with the order.

    How Your Order Is Prepared for Shipping

    Before dispatch, your order is carefully prepared to help ensure it arrives safely and in the expected condition.

    • The selected SKU and order details are reviewed.
    • The item is visually checked for obvious external damage.
    • All included components are confirmed where applicable.
    • Protective packaging is used around vulnerable areas.
    • The product is secured inside the shipping carton to reduce movement during transit.
    • The outer carton and shipping label are checked before carrier pickup.
    • Tracking information is provided after the shipment has been processed.
    • Any special delivery or core-return instructions are communicated separately when applicable.

    Please inspect the package immediately after delivery. If the carton or product shows visible damage, take clear photographs before installation and contact Mariners Warehouse promptly.

    Quick Fitment Summary

    Specification OBR Mercury 4-Stroke Lower Unit | 115 HP 2001–2006 & 75–115 HP 2007–2014
    Manufacturer / Brand OBR Parts
    Compatible Engine Make Mercury
    Product Type Replacement outboard lower unit / gearcase
    Engine Architecture Four-cylinder four-stroke
    2001–2003 Application Mercury 115 HP four-stroke; serial range 0T178500–0T800999
    2004–2006 Application Mercury 115 HP four-stroke
    2007–2014 Application Selected Mercury 75 HP, 90 HP and 115 HP four-stroke outboards
    Condition Options New and remanufactured
    Shaft Length Options 20-inch L and 25-inch XL
    Rotation / Configuration Standard configuration; verify using the complete engine serial number
    Gear Ratio 2.07:1 for verified 115 HP applications; VERIFY BEFORE PUBLISHING for 75/90 HP 2007–2014 SKUs
    New 2001–2003 SKUs ME-G4-06-N for 20-inch L and ME-G4-06A-N for 25-inch XL
    Remanufactured 2001–2003 SKUs ME-G4-06-R for 20-inch L and ME-G4-06A-R for 25-inch XL
    New 2004–2006 SKUs ME-G4-07-N for 20-inch L and ME-G4-07A-N for 25-inch XL
    Remanufactured 2004–2006 SKUs ME-G4-07-R for 20-inch L and ME-G4-07A-R for 25-inch XL
    New 2007–2014 SKUs ME-G4-07B-N for 20-inch L and ME-G4-07C-N for 25-inch XL
    Remanufactured 2007–2014 SKUs ME-G4-07B-R for 20-inch L and ME-G4-07C-R for 25-inch XL
    Major Exclusions Mercury two-stroke, Optimax/DFI, Command Thrust, Pro XS, counter-rotation and unmatched shift-rod applications
    Required Fitment Information Complete Mercury engine serial number, horsepower, model year, engine type and existing shaft length
    Supplier Warranty 24 months; warranty terms apply
    Core Charge VERIFY BEFORE PUBLISHING with Mariners Warehouse operations

    How to Choose the Correct Mercury Four-Stroke Replacement Gearcase

    A Mercury 115 HP four-stroke lower unit must match more than the horsepower shown on the engine cowling. Mercury used different configurations across the 2001–2003, 2004–2006 and 2007–2014 production groups, so model year, shaft length and engine serial number must all be checked.

    For 2001–2003 Mercury 115 HP outboards, the 20-inch L application uses the ME-G4-06 family, while the 25-inch XL application uses ME-G4-06A. Separate ME-G4-07 and ME-G4-07A configurations cover applicable 2004–2006 115 HP engines. Selected 75 HP, 90 HP and 115 HP four-strokes from 2007–2014 use the ME-G4-07B or ME-G4-07C families, depending on shaft length.

    New and remanufactured gearcases share the same stated application within each SKU family, but their condition and part numbers differ. Before ordering, locate the complete Mercury serial number and confirm whether the existing installation uses a 20-inch or 25-inch shaft. Do not substitute an Optimax, Command Thrust, Pro XS or counter-rotation gearcase based only on horsepower.

    Application / Compatibility Guide

    Use CTRL + F or search below to find your engine model

    Loading compatibility data...

    What Customers Say

    Clear fitment process for 2005 Mercury 115 HP 4-Stroke

    The product information made it easy to confirm that this OBR unit matched my 2005 Mercury 115 HP 4-stroke. The 2.07:1 ratio, 20-inch shaft length, and serial-number checks were clearly detailed. Always verify your gear ratio before purchasing.
    Elliott Rhodes Verified buyer
    August 2026

    Helpful 4-Stroke specific model selection

    I appreciated that the OBR 75-115 HP 4-stroke lower unit options clearly distinguished between early Yamaha-based powerheads and later Mercury models. Mariners Warehouse confirmed fitment for my 2011 90 HP 4-stroke prior to shipping.
    Gideon Vance Verified buyer
    May 2026

    Direct fit for 2012 Mercury 115 HP 4-Stroke

    The unit arrived well-secured in a heavy foam-lined box. The drive shaft splines, water pump housing, and 20-inch shaft aligned perfectly on my 2012 115 HP outboard. Runs smoothly after completing the required break-in hours.
    Callum Mercer Verified buyer
    March 2026

    Solid gearcase, unboxing required extra time

    Matching the 2.07:1 gear ratio and engine year range was simple. The gearcase functions great on the water, though unbolting the protective shipping bracket took a bit of extra effort during installation.
    Julian Croft Verified buyer
    January 2026

    Reliable replacement for 2008 Mercury 75 HP 4-Stroke

    Replaced a damaged gearcase on my 2008 75 HP 4-stroke. The listing clearly outlined the shaft length options and fitment warnings. After filling with high-performance gear lube, it has run without any issues.
    Barrett Sterling Verified buyer
    October 2025

    Frequently Asked Questions

    Which Mercury engines are covered by this product family?
    The listed OBR configurations cover Mercury 115 HP four-cylinder four-strokes from 2001–2006 and selected Mercury 75 HP, 90 HP and 115 HP four-strokes from 2007–2014.
    What is the verified serial range for the 2001–2003 Mercury 115 HP application?
    The verified serial range is 0T178500 through 0T800999. The complete serial number must still be submitted with the order.
    Which SKUs fit the 2001–2003 Mercury 115 HP four-stroke?
    The 20-inch L application uses ME-G4-06-N or ME-G4-06-R. The 25-inch XL application uses ME-G4-06A-N or ME-G4-06A-R.
    Which SKUs are used for 2004–2006 Mercury 115 HP engines?
    The 20-inch L application uses ME-G4-07-N or ME-G4-07-R. The 25-inch XL application uses ME-G4-07A-N or ME-G4-07A-R. Serial verification is required.
    Which SKUs cover 2007–2014 75 HP, 90 HP and 115 HP four-strokes?
    The 20-inch L family uses ME-G4-07B-N or ME-G4-07B-R. The 25-inch XL family uses ME-G4-07C-N or ME-G4-07C-R.
    Can I choose the lower unit using horsepower and year alone?
    No. Horsepower, year, engine type, shaft length, existing gearcase configuration and the complete Mercury serial number must be checked.
    What is the difference between the L and XL versions?
    L identifies the 20-inch shaft configuration, while XL identifies the 25-inch configuration. Select the version matching the existing engine installation.
    What is the difference between new and remanufactured variants?
    Both are replacement OBR gearcases for the stated application. One is sold as new and the other as remanufactured. Their SKU, price and product condition must remain separate.
    Does this lower unit have a 2.07:1 gear ratio?
    The verified Mercury 115 HP four-stroke family uses a 2.07:1 ratio. The exact ratio for each 2007–2014 multi-horsepower OBR SKU should be confirmed from the engine serial number before the order is released.
    Will this fit a Mercury 115 Optimax?
    No. Optimax is a different DFI two-stroke application and uses a different lower-unit configuration.
    Will these SKUs fit Command Thrust, Pro XS or counter-rotation engines?
    Do not assume compatibility. Those configurations use separate application families and require exact serial-number and gearcase verification.
    What warranty applies to this lower unit?
    Current OBR supplier listings state a 24-month warranty. Written warranty, installation and claim terms should be reviewed before installation.

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