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12596A2
12596A4
12596T2
8M0168901
8M0214927
812966A3
812966A7
812966A9
9-43330
Fits Select Mercury 25-70HP Gearcase Applications
Designed for Mercury and Mariner lower unit bearing carrier assemblies. The Mercury 21700 Bearing, also listed as 31-21700, is a needle / roller bearing used in the gearcase bearing carrier area to support the propeller shaft.
Compatibility
This bearing is used across many Mercury and Mariner small to midrange outboard gearcases. OEM where-used data shows applications across multiple 25-70HP gearcase families, including 2-stroke, 4-stroke, BigFoot, and Jet models.
Application Chart
| Brand | Engine Family | Horsepower | System | Component |
|---|---|---|---|---|
| Mercury / Mariner | Small 4-Stroke Outboards | 25-30 HP | Gearcase / Lower Unit | Bearing Carrier / Prop Shaft Bearing |
| Mercury / Mariner | 2-Cyl / 3-Cyl Outboards | 35-40 HP | Gearcase / Lower Unit | Bearing Carrier / Prop Shaft Bearing |
| Mercury / Mariner | 3-Cyl / 4-Cyl Outboards | 45-60 HP | Gearcase / Lower Unit | Bearing Carrier / Prop Shaft Bearing |
| Mercury / Mariner | BigFoot / 4-Stroke Models | 40-60 HP | Gearcase / Lower Unit | Bearing Carrier / Prop Shaft Bearing |
| Mercury / Mariner | 70HP 3-Cyl Outboards | 70 HP | Gearcase / Lower Unit | Bearing Carrier / Prop Shaft Bearing |
| Mercury / Mariner | Jet Models | 30-45 Jet | Gearcase / Jet Drive | Bearing Carrier / Prop Shaft Bearing |
Always confirm compatibility using your engine serial number, gearcase type, and existing part number before ordering.
Part Numbers & Cross References
| Reference Type | Part Number |
|---|---|
| Mercury OEM Part | 21700 |
| Mercury OEM Part | 31-21700 |
| Cross Reference # | 18-1095 |
| Cross Reference # | 93-263-12 |
| Cross Reference # | 11428 |
What This Part Is Used For
This bearing is used in the lower unit bearing carrier to support the propeller shaft. A properly functioning bearing helps maintain smooth prop shaft rotation and proper gearcase operation.
Bearings are commonly inspected or replaced during lower unit rebuilds, bearing carrier service, prop shaft repair, or when gearcase noise, vibration, or wear is found.
Frequently Asked Questions
What does Mercury 21700 fit?
This bearing fits select Mercury and Mariner small to midrange gearcases, commonly in the 25-70HP range. Always verify by serial number and gearcase diagram.
Where is this bearing used?
It is used in the lower unit bearing carrier area to support the propeller shaft.
Is 21700 the same as 31-21700?
Yes. Mercury commonly lists this bearing as 31-21700.
When should this bearing be replaced?
Replace it during lower unit rebuilds or when wear, noise, corrosion, or prop shaft bearing damage is found.
Dealer Discounts & Store Policies
Dealer / Marine Industry Discounts
Are you a marine dealer or technician? We offer dealer pricing for qualified businesses.
Shipping Policy
- Free shipping on orders over $100 (continental U.S.)
- Ships via UPS, USPS, and FedEx
- 5:30 PM EST daily cutoff
- Typical delivery 1–5 business days
30-Day Return Policy
- Returns within 30 days
- Items must be unused and in original packaging
- Return authorization is required before sending items back
Contact Us
Phone: 941-721-3000
Searchable Part Numbers
Part Number: 21700
Cross Reference #: 31-21700, 18-1095, 93-263-12, 11428
Common Search Terms: Mercury 21700 bearing, Mercury 31-21700 bearing, Mercury bearing carrier bearing, Mercury prop shaft bearing
848840A1
848840T1
818290A8
818290T8
OEM Mercury Driveshaft Oil Seal Carrier
Mercury 2.5L & 3.0L EFI / DFI Gearcase Seal Carrier
This genuine OEM Mercury driveshaft oil seal carrier fits select Mercury 2.5L and 3.0L EFI and DFI outboards using compatible gearcase assemblies.
The seal carrier supports the driveshaft sealing system in the upper gearcase area to help retain gear lube and prevent water intrusion into the lower unit.
Compatible Applications
| Engine Family | Engine Type | Application | Application Notes |
|---|---|---|---|
| Mercury 2.5L | EFI Outboards | Gearcase Driveshaft Seal Area | Select high-performance lower units |
| Mercury 2.5L | DFI Outboards | Gearcase Driveshaft Seal Area | Select OptiMax applications |
| Mercury 3.0L | EFI Outboards | Gearcase Driveshaft Seal Area | Select EFI lower units |
| Mercury 3.0L | DFI Outboards | Gearcase Driveshaft Seal Area | Select OptiMax and DFI applications |
| Alpha One Gen II | Sterndrive | Upper Gear Housing | Select sterndrive applications |
Always verify your engine serial number and gearcase application before ordering lower unit sealing components.
OEM Part Numbers & Cross References
| Type | Part Number |
|---|---|
| Current Mercury OEM Number | 8M0214948 |
| Mercury Cross Reference | 807929A1 |
| Mercury Cross Reference | 807929A2 |
| Mercury Cross Reference | 815922A1 |
| Mercury Cross Reference | 815922A5 |
| Mercury Cross Reference | 821759A1 |
| Mercury Cross Reference | 821759A2 |
| Mercury Cross Reference | 821759A3 |
| Mercury Cross Reference | 821759A4 |
| Pro Marine Part Number | 65354P |
What This Driveshaft Oil Seal Carrier is Used For
This Mercury driveshaft oil seal carrier is installed in the upper area of compatible outboard gearcases and sterndrive gear housings.
The carrier supports the driveshaft oil seals and sealing surfaces while helping prevent water intrusion and gear lube leakage.
Corrosion, seal wear, damaged sealing surfaces, or improper installation can contribute to lower unit leaks and gearcase contamination.
Seal carriers are commonly replaced during lower unit rebuild service, driveshaft resealing, or when corrosion damages the seal bore area.
Key Features and Benefits
- Genuine OEM Mercury driveshaft oil seal carrier
- Fits select Mercury 2.5L and 3.0L EFI / DFI outboards
- Also fits select Alpha One Gen II sterndrive applications
- Supports proper driveshaft seal alignment
- Helps prevent water intrusion into the lower unit
- Helps retain gear lube inside the gearcase
- Common replacement during lower unit rebuild service
- OEM Mercury fit and sealing compatibility
Driveshaft Seal Carrier Details
- Brand: Mercury Marine
- Part Type: Driveshaft Oil Seal Carrier
- Current OEM Number: 8M0214948
- Cross References: 807929A1, 807929A2, 815922A1, 815922A5, 821759A1, 821759A2, 821759A3, 821759A4
- Applications: Mercury 2.5L & 3.0L EFI / DFI Outboards
- System: Lower Unit / Gearcase
- Use: Driveshaft sealing and gearcase reseal service
FAQ
What engines does this seal carrier fit?
This carrier fits select Mercury 2.5L and 3.0L EFI and DFI outboards along with certain Alpha One Gen II applications.
What does a driveshaft seal carrier do?
The seal carrier supports the driveshaft oil seals and helps prevent water intrusion and gear lube leakage inside the lower unit.
Why would this part need replacement?
Common causes include corrosion, damaged sealing surfaces, water intrusion, or lower unit rebuild service.
Does this replace older Mercury assemblies?
Yes. This carrier replaces several earlier Mercury part numbers including 807929A1, 815922A5, and 821759A4.
Should the lower unit be pressure tested after installation?
Yes. Pressure and vacuum testing is recommended after seal service to verify proper sealing.
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.
- Lower unit sealing components should be installed only after proper inspection and diagnosis.
- Items must be new, unused, and in original packaging.
- Return authorization is required before sending items back.
Need help with a return or order question?
Contact Us
Phone: 941-721-3000
Searchable Terms
65354P, 8M0214948, 807929A1, 807929A2, 815922A1, 815922A5, 821759A1, 821759A2, 821759A3, 821759A4, Mercury seal carrier, driveshaft oil seal carrier, Mercury 2.5L seal carrier, Mercury 3.0L seal carrier, Mercury EFI lower unit seal, Mercury DFI gearcase seal carrier, Mercury OptiMax seal carrier, Alpha One Gen II seal carrier
807929A1
807929A2
815922A1
815922A5
821759A1
821759A2
821759A3
821759A4
9-43714
90206
90206-22M19-00
225hp EFI
Yamaha
2 Stroke
115hp 1984-2010
130hp 1984-2004
150hp 1984-2009
175hp 1984-2000
200hp 1984-1999
225hp 1990-1997
250hp 1990-1995
S115, S130, S150, S175, S200, S225, S250
LX / LZ 150, 200, 250, 300
V150, 175, 200, 225
VZ/Z 150, 175, 200, 225, 250, 300
4 Stroke
F75 2017 & Up
F90 2016 & Up
F115 2000 & Up
F150 2004 & Up
F175 2014 & Up
F200 2002 & Up
F225 2002-2018
F250 2005-2018
8814372
93210-54M14-00
93210-54534-00
93210-55M14-00
93210-55051-00
78318
85222
888694
93101-28M16-00
30320
43047
430471
430472
8M0214931