Transom Foam Gasket Seal for MerCruiser MC-1, R, MR & Alpha One – Replaces OEM 65533A1
Transom Foam Gasket Seal for MerCruiser MC-1, R, MR & Alpha One – Replaces OEM 65533A1 is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
Orders are typically processed within 1–2 business days.
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Transom Foam Gasket Seal for MerCruiser MC-1, R, MR & Alpha One...
Transom Foam Gasket Seal for MerCruiser MC-1, R, MR & Alpha One – Replaces OEM 65533A1 is backordered and will ship as soon as it is back in stock.
Product Details
This transom foam gasket seal is a replacement sealing component for selected MerCruiser MC-1, R, MR, and Alpha One sterndrive applications. It installs at the transom and gimbal-housing mating area to help seal the assembly and limit water intrusion.
The seal replaces MerCruiser OEM part number 65533A1. GLM reference 86712 is listed for the same MC-1, R, MR, and Alpha One transom-seal application. Confirm the part number and drive configuration against your service information before ordering.
- Replacement transom foam gasket seal for the listed MerCruiser drive families.
- Designed to fit between the transom assembly and gimbal housing mating surfaces.
- Helps restore sealing where the original gasket is compressed, cracked, or deteriorated.
- Single replacement seal; this listing is not a complete transom service kit.
Part Number Matrix
Use the following references to compare the replacement seal with documented manufacturer and aftermarket catalog numbers.
| Brand or Reference | Part Number | Application Description |
|---|---|---|
| MerCruiser | 65533A1 | OEM reference for the transom seal |
| GLM | 86712 | Transom seal for MC-1, R, MR, and Alpha One |
Engine & Model Compatibility
Catalog evidence identifies this transom seal by drive family rather than by a horsepower range or a specific production-year range. Verify the drive designation and existing part number before purchase.
| Brand | Drive or Model Family | OEM Reference | Fitment Notes |
|---|---|---|---|
| MerCruiser | MC-1 | 65533A1 | Confirm the original seal and transom assembly configuration. |
| MerCruiser | R | 65533A1 | Confirm the original seal and transom assembly configuration. |
| MerCruiser | MR | 65533A1 | Confirm the original seal and transom assembly configuration. |
| MerCruiser | Alpha One | 65533A1 | Verify the drive generation and part number before ordering; Alpha One Gen II applications use different transom-seal references in catalog listings. |
Technical Specs
- Product Type
- Transom foam gasket seal
- Installation Location
- Between the transom assembly and gimbal housing mating surfaces
- Primary OEM Reference
- 65533A1
- Aftermarket Catalog Reference
- GLM 86712
- Drive Families
- MerCruiser MC-1, R, MR, and Alpha One
- Package Type
- Single replacement seal
What’s in the Box
- 1 x Transom foam gasket seal
Installation Notes
- Disconnect the negative battery terminal and follow the safety procedures in the appropriate service manual.
- Remove the sterndrive and related components as required by the manufacturer’s service procedure.
- Support and remove the gimbal housing or transom assembly as required to access the seal.
- Remove the old seal and clean the mating surfaces thoroughly. Remove old gasket residue, sealant, corrosion, and debris without damaging the surfaces.
- Compare the replacement seal with the removed part and position it in the correct orientation on the transom assembly.
- Reinstall the gimbal housing and related components. Tighten fasteners using the torque values and sequence specified in the service manual.
- Reassemble the sterndrive and any disconnected hoses, bellows, cables, or hardware.
- After launching the boat, inspect the transom area for leaks and correct any issue before operating the vessel.
Troubleshooting & FAQ
Which MerCruiser drives use this transom seal?
The documented application covers MerCruiser MC-1, R, MR, and Alpha One drive families under OEM reference 65533A1. Verify the drive generation and compare the original part before ordering. Alpha One Gen II applications may use a different seal reference.
Does this listing include a complete seal or transom service kit?
No. This listing is for one transom foam gasket seal only. It does not include a complete bellows, clamp, hardware, plug, or transom service kit.
What are common signs that the transom seal needs replacement?
Possible signs include water entering the bilge near the transom assembly, visible cracking or compression damage, and deterioration of the old gasket when the gimbal housing is removed. Diagnose the complete transom assembly before replacing any individual seal.
Can the old transom seal be reused?
Reuse is not recommended. A removed gasket may be permanently compressed or damaged and may not provide a reliable seal after reinstallation.
Is this an OEM MerCruiser part?
No. This is a replacement seal identified for use in place of OEM reference 65533A1. MerCruiser and other brand names and part numbers are used only to describe compatibility and reference the intended application.
How should I confirm fitment?
Compare the drive family, drive generation, original seal, mounting configuration, and part number with the information in your service manual. If your original part differs from the references listed here, confirm compatibility before ordering.
Shipping speed and cost
Shipping methods, delivery estimates, and costs are shown at checkout and may vary by destination.
Warranty and returns
Warranty and return terms are governed by the applicable store policy. Contact customer support before installation if the part received does not match the ordered application.
Safety & Important Information
- Confirm the drive family and part number before ordering; model names alone may not establish compatibility.
- Do not use the listed fitment as confirmation for Alpha One Gen II or other later drive configurations without checking the correct service information.
- Installation may require removal of the sterndrive and gimbal housing. Follow the manufacturer’s service manual and use the specified torque values.
- Professional installation is recommended when the required removal and alignment procedures are outside your experience.
About Sea Sierra
- Marine Replacement Parts — We supply replacement components for common marine service and repair applications.
- Application-Focused Listings — Product descriptions are organized around documented part-number and model-family references.
- Support Before Installation — Contact support if the received part does not match your original component or service-manual requirements.
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