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Description
816431A1;18-2747 U-Joint Rubber Bellow for Mercruiser Alpha One Gen 2 | JLM MarineU Joint Rubber Bellow for Mercruiser Alpha One Gen 2 Transom Seal Kit 816431A1 This U Joint Rubber Bellow is engineered for Mercruiser Alpha One Gen II Sterndrives, delivering reliable protection for the transom assembly. Designed to meet OEM specifications, this bellow ensures a secure seal and smooth operation in demanding marine environments. This kit directly replaces Mercury Marine Quicksilver OEM PN 816431A1, as well as aftermarket equivalents
U-Joint Rubber Bellow for Mercruiser Alpha One Gen 2 – Transom Seal Kit 816431A1
This U-Joint Rubber Bellow is engineered for Mercruiser Alpha One Gen II Sterndrives, delivering reliable protection for the transom assembly. Designed to meet OEM specifications, this bellow ensures a secure seal and smooth operation in demanding marine environments.
This kit directly replaces Mercury Marine/Quicksilver OEM PN 816431A1, as well as aftermarket equivalents from Sierra Marine and GLM, offering broad compatibility and cost-effective maintenance for your sterndrive system.
- Complete kit includes U-Joint bellow, sleeve, and hose clamps for straightforward installation
- Direct replacement for Mercury Marine 816431A1, Sierra 18-2747, and GLM 89180
- Precision-fit design ensures compatibility with Alpha One Gen II sterndrive transom assemblies
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand | Part Number |
|---|---|
| Mercury Marine/Mercruiser | 816431A1 |
| Sierra Marine | 18-2747 |
| GLM | 89180 |
Compatible Engine Models
Confirm your engine model/year in the table below. For Mercury owners, here's a guide to help you identify your engine's serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.
| Brand | Model |
|---|---|
| Mercruiser | Alpha One Gen II Sterndrives |
Technical Specifications
| Specification | Value |
|---|---|
| Part Type | U-Joint Rubber Bellow |
| Application | Mercruiser Alpha One Gen II Sterndrive Transom |
| OEM Replacement | 816431A1 |
Package Contents
This complete kit includes the following components:
- U-Joint Bellow
- Sleeve
- Hose Clamps
Installation Guide
- Disconnect the battery and ensure the sterndrive is securely supported on a stable stand or hoist. Remove the drive unit from the transom assembly.
- Carefully remove the old U-Joint bellow by loosening and sliding off the existing hose clamps. Inspect the U-Joint and gimbal bearing for wear or damage.
- Clean the mounting surfaces on both the transom plate and the drive shaft housing thoroughly to remove old grease, debris, and corrosion.
- Slide the new sleeve onto the drive shaft, ensuring proper alignment with the U-Joint assembly.
- Position the new U-Joint bellow over the sleeve, aligning it carefully with the transom plate and drive shaft housing grooves.
- Install the hose clamps at both ends of the bellow, tightening them evenly to the manufacturer's recommended torque specification. Ensure the bellow is seated properly without twists or kinks.
- Apply marine-grade grease to the U-Joint and gimbal bearing as specified in your service manual.
- Reinstall the sterndrive unit onto the transom, ensuring all mounting bolts are torqued to specification. Reconnect the shift and throttle cables.
- Reconnect the battery and perform a visual inspection of the bellow installation, checking for proper seating and secure clamp tension.
- Conduct a water test to verify proper operation and inspect for any signs of leakage around the bellow.
Troubleshooting & FAQ
Q: How do I confirm this bellow fits my Mercruiser sterndrive?
A: Verify that you have a Mercruiser Alpha One Gen II sterndrive and cross-reference your current part number with 816431A1, Sierra 18-2747, or GLM 89180. Always compare the bellow dimensions and profile with your original part before installation.
Q: How often should I replace the U-Joint bellow?
A: Inspect the U-Joint bellow annually as part of routine maintenance. Replace it every 2–3 years or immediately if you notice cracks, tears, swelling, or water intrusion, as a compromised bellow can lead to gimbal bearing and U-Joint failure.
Q: What are the signs that my U-Joint bellow has failed?
A: Common symptoms include water in the bilge, visible cracks or splits in the rubber, excessive play in the sterndrive, corrosion on the U-Joint or gimbal bearing, and difficulty steering. If you observe any of these, inspect and replace the bellow immediately.
Q: Can I install this bellow without removing the entire sterndrive?
A: While some experienced technicians may attempt partial removal, it is highly recommended to fully remove the sterndrive unit for proper access, cleaning, and inspection of the U-Joint and gimbal bearing. This ensures a thorough and safe installation.
Q: Is this an OEM or aftermarket part?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.
Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.
Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.
Important Notes
- Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
- This product is an aftermarket replacement part and is not an OEM component.
- Professional installation is recommended to ensure safety and optimal performance.
Why Choose JLM MARINE?
- Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
- Fast Global Shipping: Free delivery worldwide in 5–15 days.
- Direct from Manufacturer: Competitive pricing without compromising quality.
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy