Bearing Adapter Assembly – Fits Mercury/Mercruiser Alpha One Gen II (Replaces 828830A2)
Bearing Adapter Assembly – Fits Mercury/Mercruiser Alpha One Gen II (Replaces 828830A2) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
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Bearing Adapter Assembly – Fits Mercury/Mercruiser Alpha One Gen II...
Product Details
This Bearing Adapter Assembly is specifically engineered for Mercury/Mercruiser Alpha One Generation II stern drives (1991–present) that are equipped with a counter-rotation propeller shaft. It ensures correct alignment and robust support for the propeller shaft within the gear housing for reliable performance in counter-rotation applications.
It serves as a direct interchange for Mercury/Mercruiser part numbers 828830A1 and 828830A2, and is also an equivalent cross-reference for SEI Marine part 98-208-80.
- Installation Location: Propeller Shaft (Counter Rotation Gearcase)
- Primary Application: Alpha One Gen II (Counter Rotation only)
- Weight: 0.56 kg (1.23 lb)
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Superseded By | Notes |
|---|---|---|---|
| Mercury/Mercruiser | 828830A1 | 828830A2 | Original part number. |
| Mercury/Mercruiser | 828830A2 | Current active OEM part. | |
| SEI Marine | 98-208-80 | Aftermarket replacement. |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This part is designed exclusively for Mercury/Mercruiser Alpha One Generation II stern drives with counter-rotation.
| Brand | Model | Years | OEM Part No. | Notes |
|---|---|---|---|---|
| Mercury/Mercruiser | ALPHA ONE (GEN. II) | 1991–1995 | 828830A2 | Serial range: 0D469859-0F679999 |
| Mercury/Mercruiser | ALPHA ONE (GEN. II) | 1996–1997 | 828830A2 | Serial range: 0F680000-0K999999 |
| Mercury/Mercruiser | ALPHA ONE (GEN. II) | 1998–Present | 828830A2 | Serial range: 0L100040 & Up |
Technical Specs
- Product Type
- Bearing Adapter Assembly
- Installation
- Propeller Shaft (Counter Rotation)
- Weight
- 0.56 kg (1.23 lb)
- Dimensions
- 9.5 (L) x 10.0 (W) x 5.0 (H)
- Fitting Type
- Counter Rotation Propeller Shaft
- Other Technical Attributes
- Used specifically in counter-rotation applications
What’s in the Box
- 1 x ADAPTER ASSEMBLY Bearing (828830A2)
Installation Notes
This bearing adapter assembly is installed inside the gear housing on the propeller shaft. It is specifically located within the counter-rotation gear case of Mercury/Mercruiser Alpha One Generation II stern drives. Ensure the existing bearing and seals are carefully removed before pressing in the new assembly using appropriate tools as outlined in your official service manual.
Troubleshooting & FAQ
What is this adapter's specific application?
This bearing adapter is exclusively for Mercury/Mercruiser Alpha One Generation II stern drives manufactured from 1991 to the present that are equipped with a counter-rotation gearcase.
Will this fit a standard (right-hand) rotation Alpha One Gen II?
No. This part is engineered only for counter-rotation (left-hand) models. Using it in a standard rotation drive will lead to incorrect propeller shaft alignment and gearcase failure.
What does "counter-rotation" mean for this part?
Counter-rotation refers to a dual-propeller stern drive where one propeller spins left (port) and the other spins right (starboard). This adapter is for the gearcase that drives the left-hand (counter-rotating) propeller shaft. It is not interchangeable with standard rotation parts.
Is this a direct replacement for part number 828830A1?
Yes, OEM part 828830A2 is the official superseded replacement for 828830A1. This aftermarket part is built to those specifications and provides a direct fit with no modifications required.
What are the signs of a failing bearing adapter?
Common symptoms include excessive vibration from the stern drive, a grinding or rumbling noise that changes with engine RPM, or visible metal shavings in the gear lube. A loose or wobbling propeller shaft when tested by hand can also indicate a worn bearing.
Does this assembly include everything needed for installation?
The package contains the bearing adapter assembly itself. Associated seals, o-rings, or shims must be purchased separately. Always refer to your service manual for a complete list of required parts for the job.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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