Upper Unit Seal Kit for MerCruiser Bravo I, II, III, X, XR, XZ & Blackhawk – Replaces 26-16709A1, 26-16709A2
Upper Unit Seal Kit for MerCruiser Bravo I, II, III, X, XR, XZ & Blackhawk – Replaces 26-16709A1, 26-16709A2 is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
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Upper Unit Seal Kit for MerCruiser Bravo I, II, III, X, XR, XZ &...
Upper Unit Seal Kit for MerCruiser Bravo I, II, III, X, XR, XZ & Blackhawk – Replaces 26-16709A1, 26-16709A2 is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket Upper Unit Seal Kit is designed for the drive shaft housing and upper-unit sealing service of selected MerCruiser Bravo stern drives. Catalog references identify this application as compatible with Bravo I, Bravo II, Bravo III, Bravo X, Bravo XR, Bravo XZ, and Blackhawk drives when the model, year, and serial-number conditions below are met.
The kit is listed as a replacement for MerCruiser OEM numbers 26-16709A1 and 26-16709A2. It is also cross-referenced to Sierra 18-2643 and GLM 87480. This is an aftermarket replacement part and is not manufactured by MerCruiser, Sierra, or GLM.
- Upper unit and drive shaft housing seal kit for selected MerCruiser Bravo applications.
- Designed to replace the listed OEM seal-kit references.
- Suitable for service or resealing work where the application and serial range match.
- Professional installation is recommended because upper-unit disassembly and seal installation require appropriate service procedures and tools.
Part Number Matrix
Use the following references when comparing the required seal kit with the part being removed.
| Brand | Part Number | Reference Type |
|---|---|---|
| MerCruiser | 26-16709A1 | OEM replacement reference |
| MerCruiser | 26-16709A2 | OEM replacement reference |
| Sierra | 18-2643 | Aftermarket cross-reference |
| GLM | 87480 | Aftermarket cross-reference |
Engine & Model Compatibility
Confirm both the drive model and the serial number before ordering. The model, year, and serial-number conditions must be considered together.
| Drive Model | Years | Serial Number Condition | Applicable Kit Reference |
|---|---|---|---|
| MerCruiser Bravo I | 1988 and up | 0B664190 and up | 87480 / 18-2643 |
| MerCruiser Bravo II | 1988 and up | 0B664190 and up | 87480 / 18-2643 |
| MerCruiser Bravo III | 1988 and up | 0B664190 and up | 87480 / 18-2643 |
| MerCruiser Blackhawk | 1994–1995 | 0F186717 and up | 87480 / 18-2643 |
| MerCruiser Bravo X, XR & XZ | Application listed in aftermarket catalog references | Verify the exact drive serial number | 87480 / 18-2643 |
Technical Specifications
- Product Type
- Upper unit seal kit
- Service Area
- Drive shaft housing and upper gearcase sealing system
- Drive Family
- MerCruiser Bravo stern drives
- Compatible Models
- Bravo I, Bravo II, Bravo III, Bravo X, Bravo XR, Bravo XZ and Blackhawk, subject to the application conditions above
- OEM Replacement References
- 26-16709A1 and 26-16709A2
- Aftermarket References
- Sierra 18-2643 and GLM 87480
- Construction
- Seal-kit components for upper-unit service; individual materials and dimensions are not specified in the available catalog records
What’s in the Box
One upper unit seal kit for the application described above. The available catalog records identify this product as a complete seal kit but do not provide a verified item-by-item component list or quantity breakdown for this exact aftermarket listing. Do not assume that components from a different lower-unit or Alpha drive seal kit are included.
Installation Notes
- Confirm the drive model, year, serial number, and existing seal-kit reference before beginning work.
- Place the drive in the appropriate service position and drain the gear lubricant according to the service manual.
- Remove the upper unit or drive shaft housing using the procedure specified for your MerCruiser drive.
- Keep removed components in order and note the orientation of seals, washers, retainers, and related parts.
- Remove the old seals, O-rings, and gaskets without damaging the housing or sealing surfaces.
- Clean and inspect all mating surfaces, bores, shafts, and related components for corrosion, scoring, fishing line, debris, or other damage.
- Lubricate replacement seals and O-rings only as directed by the applicable service manual.
- Install each seal squarely with the correct seal driver or equivalent installation tool. Do not force a seal into an incorrect location or orientation.
- Reassemble the upper unit in the correct order and torque fasteners to the manufacturer's specified values.
- Pressure-test the housing for leaks before reinstalling the drive and refill it with the specified marine gear lubricant.
Troubleshooting & FAQ
What does this kit service?
This is an upper unit or drive shaft housing seal kit for selected MerCruiser Bravo applications. It is not a general-purpose kit for every MerCruiser drive and should not be substituted for an Alpha, MR, lower-unit, or bell-housing kit.
Which OEM numbers does this kit replace?
The catalog references identify MerCruiser 26-16709A1 and 26-16709A2 as replacement references. Sierra 18-2643 and GLM 87480 are corresponding aftermarket cross-references.
Does it fit every Bravo drive?
No. The documented applications include Bravo I, Bravo II, and Bravo III from 1988 and up with serial number 0B664190 and up, plus Blackhawk applications from 1994–1995 with serial number 0F186717 and up. Bravo X, XR, and XZ applications are listed in the cross-reference material, but the exact drive serial number should still be checked before ordering.
What are common signs that the upper unit needs resealing?
Possible signs include milky or water-contaminated gear lubricant, visible lubricant leakage, repeated lubricant loss, or a failed pressure test. These symptoms can also result from damaged housings, shafts, bearings, or other components, so inspect the complete drive.
Are special tools required?
Upper-unit seal service may require seal drivers, specialty drive tools, a calibrated torque wrench, and pressure-testing equipment. Follow the correct service manual for the drive being repaired.
Is this an OEM part?
No. This listing is for an aftermarket replacement seal kit. MerCruiser, Sierra, and GLM references are used only to identify the application and comparable part references.
Safety & Important Information
- Verify the exact drive model, year, and serial number before purchase.
- Compare the removed kit and application references before installation.
- Do not use this upper-unit kit in place of a lower-unit, Alpha, MR, bell-housing, or other seal kit.
- Follow the applicable service manual for disassembly, seal orientation, lubricant type, pressure testing, and torque specifications.
- Professional installation is recommended if the drive has not previously been disassembled or pressure-tested.
About Sea Sierra
- Marine Parts Selection — We provide aftermarket marine replacement parts for service and repair applications.
- Application-Focused Listings — Product references and compatibility information are presented to help you compare the part with your existing drive.
- Service-Minded Support — Confirm your model and serial-number details before ordering when application coverage is not exact.
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