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Mercury Outboard Parts
Shop OEM and aftermarket Mercury outboard parts for maintenance, repair, troubleshooting, and complete engine rebuild projects. Browse Mercury marine parts by system, including cooling, fuel delivery, electrical and ignition, internal engine components, lower unit parts, steering, trim, and routine service items.
Pro Marine USA carries Mercury outboard engine parts for a wide range of 2-stroke, FourStroke, EFI, Optimax, Pro XS, SeaPro, and Verado applications. Use your engine horsepower, model, serial number, or OEM part number whenever possible to confirm fitment before ordering.
Shop Mercury Outboard Parts by System
- Complete Powerheads
- Control Cables & Boxes
- Cooling System
- Cowlings & Components
- Electrical System
- Engine Oil
- Engine Rebuild Kits
- Fuel & Carburetion System
- Intake System
- Internal Engine Components
- Lower Unit Components
- Oiling System
- Paints
- Service & Oil Change Kits
- Service Manuals
- Steering Systems
- Throttle Components
- Transom & Midsection
- Trim System
- Wizard Performance Parts
Find the Correct Mercury Outboard Part
Mercury outboard parts can vary by horsepower, engine family, model year, and serial number range. If you are unsure which component fits your engine, use the OEM parts lookup to locate the original Mercury part number from an engine diagram.
Once you have the OEM part number, search Pro Marine to find available genuine Mercury and aftermarket replacement options.
Use Our OEM Parts Lookup »Common Mercury Outboard Engine Families
Pro Marine supports many Mercury outboard applications across a wide horsepower range. Always confirm the engine serial number and model information before ordering parts.
- Portable and Midrange: Mercury 2.5HP through 60HP 2-stroke and FourStroke applications
- FourStroke and EFI: common 75HP through 300HP Mercury EFI and FourStroke platforms
- Pro XS: performance-oriented Mercury Pro XS outboards across multiple engine families
- Optimax: direct-injected 2-stroke Mercury Optimax engines, commonly 75HP through 250HP
- Verado: supercharged and naturally aspirated Mercury Verado applications from 135HP through current high-horsepower platforms
- SeaPro: commercial-duty Mercury SeaPro outboards used in professional and high-hour applications
Common Mercury Outboard Repair Areas
- Overheating: inspect the water pump, impeller, thermostat, poppet valve, cooling passages, and related cooling components.
- Hard starting or rough running: inspect fuel pumps, filters, injectors or carburetors, spark plugs, coils, sensors, and intake components.
- No spark or intermittent ignition: check ignition coils, stators, switch boxes, trigger assemblies, sensors, grounds, and wiring.
- Low compression or power loss: inspect pistons, rings, cylinders, bearings, gaskets, reeds, and internal engine components.
- Lower unit noise or water intrusion: inspect seals, bearings, gears, shafts, bearing carriers, and gear lube condition.
- Trim or steering problems: inspect trim motors, pumps, hydraulic components, steering cylinders, hoses, and related rigging parts.
Why Buy Mercury Outboard Parts from Pro Marine USA?
- OEM Mercury and aftermarket replacement options for many common applications.
- Parts for maintenance, repair, engine rebuilding, lower units, electrical systems, fuel systems, steering, trim, and rigging.
- OEM diagram and part-number lookup tools to help identify the correct part before ordering.
- Dealer pricing available for qualified marine repair businesses and dealers.
- Large inventory of Mercury service parts and hard-to-find marine engine components.
- Fast weekday shipping on qualifying in-stock orders.
Frequently Asked Questions
How do I find the correct Mercury outboard part?
Use the engine horsepower, model, serial number, and year whenever available. Mercury frequently uses serial-number ranges to identify engine families, so the serial number is often the most reliable way to confirm fitment.
Can I search Mercury parts by OEM part number?
Yes. Enter the Mercury OEM part number into the Pro Marine site search to locate available OEM and aftermarket replacement options. If you do not know the part number, use the OEM parts lookup first.
Do Mercury outboard parts vary by serial number?
Yes. Many Mercury components change by serial-number range even within the same horsepower or model family. Always compare the serial range listed for the part with your engine before ordering.
Do you carry parts for Mercury Optimax and Verado engines?
Yes. Pro Marine carries parts for many Mercury Optimax, Verado, Pro XS, EFI, FourStroke, and SeaPro applications, including maintenance, fuel, electrical, cooling, internal engine, lower unit, steering, and rigging components.
Do you carry both OEM and aftermarket Mercury parts?
Yes. Pro Marine offers genuine Mercury parts along with aftermarket replacement parts for many common Mercury outboard maintenance, repair, and rebuild applications.
What Mercury outboard parts are commonly replaced during routine maintenance?
Common maintenance items include engine oil, oil filters, fuel filters, spark plugs, water pump kits, impellers, thermostats, gear lube, drain plug seals, anodes, and manufacturer-specific service kit components.
Fitment Tip: Mercury outboard parts often vary by serial-number range. Confirm your engine serial number and OEM part number whenever possible before ordering.
18-6420
3AA760100
3AA760100M
3421
5040343
6L2-81800-10-00
6L2-81800-11-00
6L2-81800-20-00
682-81800-11-00
682-81800-12-00
8M0223446
8M6007363
803835T02
18-6412
31100-95240
31100-95241
31100-95242
31100-95243
31100-95244
697-81800-11-00
697-81800-12-00
8M0033984
81490M
893889T
90983A1
90983T1
92669M
97072M
97072T
99999-03249-00
885342001
885342002
8M0142542
8M0205787
Mercury Racing Lower Unit and Gearcase
Mercury Racing 8M0176859 5.44 Inch XL Gearcase
Mercury Racing 8M0176859 is a 5.44 inch XL gearcase assembly with a 1.60 gear ratio and standard rotation. It is used on Mercury Racing 450R supercharged 4.6L V8 Verado platform applications.
This current Mercury Racing gearcase supersedes 8M0159651. Because complete lower unit assemblies are highly specific to shaft length, gear ratio, rotation, engine family, and serial number, confirm your exact application before ordering.
Compatible Applications
| Brand | Engine / System | Application | Fitment Note |
|---|---|---|---|
| Mercury Racing | 450R Supercharged 4.6L V8 | 5.44 inch XL gearcase, 1.60 ratio, standard rotation | Verify by serial number, shaft length, ratio, and rotation |
| Mercury Racing | High-Horsepower 4.6L V8 Performance Models | Select applications requiring XL shaft and 1.60 standard rotation gearcase | Confirm the OEM parts diagram for your engine serial number |
Important Fitment Note
Always confirm compatibility using your engine serial number, model, existing gearcase number, shaft length, gear ratio, and rotation before ordering. XL, counter rotation, standard rotation, and ratio differences are not interchangeable.
OEM & Cross Reference Numbers
| Current Mercury Racing OEM Number | 8M0176859 |
| Superseded From | 8M0159651 |
| Description | 5.44 inch XL gearcase, 1.60 ratio, standard rotation |
What This Part Is Used For
This is a complete lower unit gearcase assembly used to transfer engine power through the driveshaft and gear set to the propeller shaft. The 1.60 gear ratio and standard rotation configuration are designed for specific Mercury Racing performance setups.
Replacement may be required after gearcase impact damage, internal gear failure, bearing damage, housing damage, or a complete lower unit service decision where assembly replacement is preferred over rebuilding.
Key Features and Benefits
- Genuine Mercury Racing gearcase assembly
- Current part number 8M0176859
- Supersedes Mercury Racing 8M0159651
- 5.44 inch gearcase for high-performance applications
- XL shaft configuration
- 1.60 gear ratio with standard rotation
- Designed for select Mercury Racing 450R and 4.6L V8 performance models
- Best verified by serial number, shaft length, ratio, and rotation
FAQ
What does Mercury Racing 8M0176859 replace?
Mercury Racing 8M0176859 supersedes 8M0159651 for this 5.44 inch XL, 1.60 ratio, standard rotation gearcase application.
Does this fit the Mercury Racing 450R?
This gearcase is used on Mercury Racing 450R supercharged 4.6L V8 applications that require the XL shaft, 1.60 gear ratio, and standard rotation gearcase.
Is this the same as a counter rotation gearcase?
No. This page is for the standard rotation version. Counter rotation gearcases use different part numbers and must be matched to the correct engine and boat setup.
What should I verify before ordering?
Verify your engine serial number, shaft length, rotation, gear ratio, and current gearcase part number. Complete gearcase assemblies are application specific and should not be selected by horsepower alone.
Dealer Discounts & Store Policies
Dealer / Marine Industry Discounts
Are you a marine dealer, technician, boat builder, or industry professional? We offer dealer pricing for qualified marine businesses.
Shipping Policy
- Free shipping on orders over $100 continental U.S.
- Orders ship via UPS, USPS, and FedEx.
- Orders received before 5:30 PM EST ship the same business day.
- Typical delivery time is 1-5 business days.
30-Day Return Policy
- Returns accepted within 30 days of delivery.
- Parts must be new, unused, and in original packaging.
- Installed parts are not returnable.
- Return authorization is required before sending items back.
Need help with a return or order question?
Contact Us
Phone: 941-721-3000
Searchable Terms
Mercury Racing 450R gearcase, Mercury 450R lower unit, Mercury Racing XL gearcase, 5.44 inch gearcase, 1.60 ratio Mercury gearcase, Mercury standard rotation gearcase, Mercury V8 Racing lower unit, 450R standard rotation lower unit
Searchable Part Numbers
8M0176859, 8M0159651, Mercury Racing 8M0176859, Mercury Racing 8M0159651
8M0176859
8M0236145
8M0250689
OEM Mercury Premium Gear Lube
SAE 80W90 Marine Gearcase Lubricant
Mercury Premium Gear Lube 80W90 is engineered to protect marine lower units and sterndrives against wear, corrosion, foaming, and water contamination.
Mercury part number 858058K01 is designed for recreational marine applications requiring SAE 80W90 marine gear lubricant protection.
Compatible Applications
| Application | System Type | Use | Notes |
|---|---|---|---|
| Mercury Outboards | Lower Unit / Gearcase | Gear Lubrication | For compatible recreational outboard applications |
| Mercury Sterndrives | Sterndrive Lower Unit | Gear Lubrication | Compatible with many MerCruiser applications |
| Mariner Outboards | Gearcase | Gear Protection | Select compatible lower units |
| Marine Lower Units | Hypoid Gear Systems | Lubrication & Wear Protection | SAE 80W90 marine gear oil applications |
For racing, surfacing propeller, high-horsepower, or extreme-duty gearcase applications, Mercury also offers Extreme Performance 85W90 Gear Lube.
View Mercury Extreme Performance Gear Lube 85W90
OEM Part Numbers & Product Information
| Type | Details |
|---|---|
| Mercury Part Number | 858058K01 |
| Product Type | Premium Marine Gear Lube |
| Viscosity | SAE 80W90 |
| Container Size | 1 Quart |
| Brand | Mercury Marine |
What This Gear Lube is Used For
Mercury Premium Gear Lube is used to lubricate and protect marine lower units and sterndrives operating in freshwater and saltwater boating environments.
Marine gearcases operate under heavy load and elevated temperatures, making proper lubrication critical for protecting gears, bearings, shafts, and seals from wear and premature damage.
This SAE 80W90 marine lubricant helps reduce friction, resist foaming, minimize corrosion, and provide protection against water intrusion contamination.
Routine lower unit lubricant changes are an important part of preventive marine maintenance and help extend gearcase service life.
Key Features and Benefits
- OEM Mercury Premium Gear Lube
- SAE 80W90 marine gear lubricant
- Designed for Mercury outboards and sterndrives
- Helps protect gears and bearings against wear
- Excellent rust and corrosion protection
- Helps resist foaming and lubricant breakdown
- Provides protection against water contamination
- Ideal for recreational marine lower unit applications
Gear Lube Details
- Brand: Mercury Marine
- Part Number: 858058K01
- Product Type: Premium Marine Gear Lubricant
- Viscosity: SAE 80W90
- Container Size: 1 Quart
- Use: Lower Unit & Sterndrive Lubrication
- Applications: Mercury & Mariner Marine Gearcases
- Environment: Freshwater & Saltwater
FAQ
What is Mercury Premium Gear Lube used for?
This lubricant is used in marine lower units and sterndrives to protect gears, bearings, and internal gearcase components.
What viscosity is this gear lube?
This is SAE 80W90 marine gear lubricant.
When should Mercury Extreme Performance Gear Lube be used instead?
Mercury Extreme Performance Gear Lube is intended for racing, surfacing propeller, and high-performance gearcase applications operating under extreme load and temperature conditions.
Can this be used in saltwater applications?
Yes. Mercury Premium Gear Lube is formulated for both freshwater and saltwater marine environments.
When should lower unit lubricant be changed?
Mercury recommends regular lower unit service intervals as part of routine preventive maintenance.
Dealer Discounts & Store Policies
Dealer / Marine Industry Discounts
Are you a marine dealer, technician, boat builder, or industry professional? We offer dealer pricing for qualified marine businesses.
Shipping Policy
- Free shipping on orders over $100 continental U.S.
- Orders ship via UPS, USPS, and FedEx.
- Orders received before 5:30 PM EST ship the same business day.
- Typical delivery time is 1–5 business days.
30-Day Return Policy
- Returns accepted within 30 days of delivery.
- Lubricants and chemicals must remain unopened and unused for return eligibility.
- Items must be in original packaging and resalable condition.
- Return authorization is required before sending items back.
Need help with a return or order question?
Contact Us
Phone: 941-721-3000
Searchable Terms
858058K01, Mercury gear lube, Mercury Premium Gear Lube, Mercury 80W90, Mercury lower unit oil, Mercury marine gear oil, Mercury sterndrive gear lube, SAE 80W90 marine lubricant, Mercury outboard gear oil, Mercury lower unit lubricant, marine gearcase oil, Mercury gearcase lubricant, Mercury Extreme Performance Gear Lube, Mercury racing gear oil
19007A12
3442112
5265512
6324212
6862312
75601A12
7560112
802846A1
802846Q1
858058KC1
858058K01
858058QB1
858058QC1
858058Q01
883661A1
883672A1
9-82401
807929A1
807929A2
815922A1
815922A5
821759A1
821759A2
821759A3
821759A4
8M6003194
878187
Mercury SAE 10W30 Full Synthetic Marine Engine Oil
Mercury 10W30 Full Synthetic 4-Stroke Marine Engine Oil
Mercury 8M0173224 SAE 10W30 Full Synthetic Marine Engine Oil is designed for customers wanting maximum protection for compatible non-catalyzed Mercury 4-stroke marine engines.
This advanced full synthetic marine oil formula delivers outstanding viscosity retention, corrosion protection, thermal stability, and engine wear protection across a broad range of marine operating conditions.
Compatible Applications
| Engine Type | Application | Oil Type |
|---|---|---|
| 4-Stroke Outboards | Compatible non-catalyzed Mercury outboards | SAE 10W30 Full Synthetic |
| Sterndrives | Compatible non-catalyzed Mercury sterndrive engines | SAE 10W30 Full Synthetic |
| Inboard Engines | Compatible non-catalyzed Mercury inboards | SAE 10W30 Full Synthetic |
Mercury SAE 10W30 Full Synthetic marine engine oil is intended for non-catalyzed 4-stroke marine engines.
Always verify the recommended oil viscosity and specification in your owner's manual before use.
Why Use Mercury Full Synthetic Marine Oil?
Mercury SAE 10W30 Full Synthetic marine engine oil is formulated to provide maximum protection for hard-working marine engines operating under heavy loads and harsh marine conditions.
Compared to Mercury 10W30 synthetic blend marine oil, this advanced full synthetic formula includes:
- 49% more anti-wear additives
- 45% more dispersants
- 24% more detergents
The result is outstanding protection against corrosion, sludge formation, varnish buildup, engine wear, and thermal breakdown.
Elevated ZDDP levels and Mercury's advanced multi-grade formulation help improve shear resistance and viscosity retention across a broad range of temperatures and marine operating conditions.
Key Features and Benefits
- Mercury SAE 10W30 Full Synthetic marine engine oil
- Designed for non-catalyzed 4-stroke marine engines
- Suitable for outboards, sterndrives, and inboards
- Advanced full synthetic marine oil formulation
- Outstanding viscosity retention for maximum engine protection
- Enhanced protection against engine wear and thermal breakdown
- Elevated zinc and phosphorous levels for anti-wear protection
- Helps reduce sludge and varnish buildup
- Excellent corrosion protection for marine environments
- Compatible with mineral and synthetic blend 10W30 formulas
- Safe upgrade path from conventional or synthetic blend oil
Oil Specifications
| Specification | Details |
|---|---|
| Part Number | 8M0173224 |
| Oil Type | Full Synthetic Marine Engine Oil |
| Viscosity | SAE 10W30 |
| Application | Non-Catalyzed 4-Stroke Marine Engines |
| Engine Types | Outboards, Sterndrives, and Inboards |
| Additive Package | Elevated ZDDP / Marine Anti-Wear Formula |
| Compatibility | Compatible with mineral and synthetic blend 10W30 oils |
What This Oil is Used For
Mercury SAE 10W30 Full Synthetic marine engine oil is designed for high-performance lubrication and protection of compatible non-catalyzed 4-stroke marine engines.
Marine engines operate under higher sustained loads and more demanding conditions than many automotive applications. This full synthetic formula is engineered to help maintain viscosity stability, corrosion protection, and wear resistance in harsh marine environments.
It is commonly used in compatible Mercury outboards, sterndrives, and inboard engines requiring SAE 10W30 marine oil.
FAQ
What engines can use Mercury SAE 10W30 Full Synthetic oil?
This oil is designed for compatible non-catalyzed 4-stroke outboards,
sterndrives, and inboard marine engines.
Is this oil full synthetic?
Yes. Mercury 8M0173224 is a full synthetic marine engine oil.
Can this oil be mixed with synthetic blend or conventional oil?
Yes. Mercury states this oil is compatible with mineral and synthetic blend
10W30 formulas for safe upgrading.
What makes this oil different from Mercury synthetic blend oil?
This full synthetic formula contains increased anti-wear additives,
dispersants, and detergents for improved engine protection and performance.
Does this oil help protect against corrosion?
Yes. This formula is specifically designed to help protect marine engines
against corrosion, thermal breakdown, sludge, and engine wear.
Should I verify viscosity before use?
Yes. Always verify the correct oil viscosity and specification
recommended by your engine manufacturer before use.
Dealer Discounts & Store Policies
Dealer / Marine Industry Discounts
Are you a marine dealer, technician, boat builder, or industry professional? We offer dealer pricing for qualified marine businesses.
Shipping Policy
- Free shipping on orders over $100 continental U.S.
- Orders ship via UPS, USPS, and FedEx.
- Orders received before 5:30 PM EST ship the same business day.
- Typical delivery time is 1–5 business days.
30-Day Return Policy
- Returns accepted within 30 days of delivery.
- Items must be new and unopened in original packaging.
- Opened oil and lubricants may not be returnable.
- Return authorization is required before sending items back.
Need help with a return or order question?
Contact Us
Phone: 941-721-3000
Searchable Terms
8M0173224, Mercury 10W30 full synthetic oil, Mercury SAE 10W30 marine engine oil, Mercury full synthetic marine oil, Mercury 4-stroke marine oil, Mercury sterndrive oil, Mercury inboard engine oil, Mercury outboard oil, Mercury full synthetic 10W30, Mercury marine lubricant, Mercury engine oil, Mercury synthetic marine oil, SAE 10W30 marine oil, Mercury ZDDP marine oil, Mercury non-catalyzed engine oil
840836A1
840836A2
- Formulated to protect against corrosion and excessive wear
- Designed for use with all four-stroke marine engines when 10W-30 is recommended
- Offers outstanding strength and viscosity retention
- 1-gallon bottle
- Produced by Mercury Marine to Mercury's stringent original equipment manufacturer specifications
- Mercury oils, lubricants and engine care products are backed by decades of experience in engineering, testing and manufacturing to provide the best protection and performance.
- Formulated to protect against corrosion and excessive wear
- Designed for use with all four-stroke marine engines when 10W-30 is recommended
- Offers outstanding strength and viscosity retention
- 1-Quart bottle
- Produced by Mercury Marine to Mercury's stringent original equipment manufacturer specifications
- Mercury oils, lubricants and engine care products are backed by decades of experience in engineering, testing and manufacturing to provide the best protection and performance.