Aftermarket Exhaust Bellows for MerCruiser Alpha One, Gen II, TRS & Bravo I, II, III – Replaces 18654A1, 32734A3
Aftermarket Exhaust Bellows for MerCruiser Alpha One, Gen II, TRS & Bravo I, II, III – Replaces 18654A1, 32734A3 is backordered and will ship as soon as it is back in stock.
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Aftermarket Exhaust Bellows for MerCruiser Alpha One, Gen II, TRS &...
Aftermarket Exhaust Bellows for MerCruiser Alpha One, Gen II, TRS & Bravo I, II, III – Replaces 18654A1, 32734A3 is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket exhaust bellows is designed for a wide range of MerCruiser sterndrive applications. It fits All #1 units, Alpha One Gen II, TRS, and Bravo I, II, and III models when the original exhaust-bellows application matches the references listed below.
The bellows forms a flexible connection between the transom plate and bell housing, helping protect the exhaust passage and maintain a sealed installation. Its ribbed rubber construction allows the assembly to flex during normal sterndrive movement.
- Aftermarket replacement for the MerCruiser exhaust-bellows application.
- Fits All #1 units, Alpha One Gen II, TRS, and Bravo I, II, and III applications listed in the compatibility information.
- Designed for installation between the transom plate and bell housing.
- Use the original component, engine-drive configuration, and serial number to confirm fitment before ordering.
Part Number References
The following references are associated with this exhaust-bellows application. They identify the component or aftermarket equivalent and should not be confused with the product's internal stock identifier.
| Brand | Part Number | Reference Type | Description |
|---|---|---|---|
| MerCruiser | 18654A1 | OEM reference | Exhaust bellows reference |
| MerCruiser | 32734A3 | OEM reference | Exhaust bellows reference |
| MerCruiser | 8M0124227 | OEM reference | Exhaust bellows reference used for Alpha One Gen II applications |
| Sierra | 18-2750 | Aftermarket reference | Exhaust bellows |
| GLM | 89100 | Aftermarket reference | Exhaust bellow |
Engine and Sterndrive Compatibility
Compatibility is determined by the sterndrive configuration and serial-number range, not by horsepower alone. Match your original exhaust bellows and verify the complete serial range before installation.
| Brand | Drive or Model | Years / Serial Conditions | Applicable Reference | Notes |
|---|---|---|---|---|
| MerCruiser | All #1 Units | Application-dependent | 18654A1 / 32734A3 | Confirm the original exhaust-bellows configuration. |
| MerCruiser | Alpha One Gen II | 1991 and later; serial 0D469859 and up | 8M0124227 | Verify the serial number and original component before ordering. |
| MerCruiser | Bravo I, II and III | 1988 and later; serial 0B664190 and up | 18654A1 / 32734A3 | Confirm the bellows arrangement on the specific drive. |
| MerCruiser | TRS | Application-dependent | 18654A1 / 32734A3 | Use the original part and serial information for final confirmation. |
| MerCruiser | Blackhawk | 1994–1995; serial 0F186717 and up | Application-dependent | Confirm the original exhaust-bellows configuration before purchase. |
| MerCruiser | R, MR and early Alpha One | 1983–1990; application-dependent | 18654A1 / 32734A3 | Check the original exhaust-bellows reference and serial range. |
Technical Specifications
- Product Type
- Exhaust bellows
- Product Construction
- Flexible ribbed rubber bellows
- Installation Location
- Between the transom plate and bell housing
- Application
- MerCruiser sterndrive exhaust-bellows systems
- Aftermarket Status
- Aftermarket replacement; not an OEM-branded component
What’s in the Box
- 1 x Exhaust bellows
Clamp and grounding-clip contents can vary by manufacturer and package configuration. Confirm the supplied components against the product photos and package contents before installation; do not assume that unrelated universal-joint-bellows hardware is included.
Installation Notes
- Disconnect the boat battery and follow appropriate marine-service safety procedures.
- Raise or support the sterndrive as specified by the manufacturer's service manual.
- Remove the sterndrive assembly according to the service manual for the specific drive.
- Remove the existing exhaust bellows and inspect the mating surfaces, clamps, and adjacent bellows for corrosion or damage.
- Clean the transom-plate and bell-housing mounting areas thoroughly.
- Position the replacement exhaust bellows correctly on both mating surfaces.
- Secure the bellows with the correct clamps or hardware specified for the particular drive configuration.
- Reinstall the sterndrive and tighten all fasteners according to the manufacturer's service specifications.
- Reconnect the battery and inspect the installation carefully before returning the boat to service.
Maintenance and Troubleshooting
What are common signs of exhaust-bellows failure?
Inspect for cracks, splits, hardening, abrasion, loose ends, or deterioration of the rubber. Any damaged bellows should be replaced before continued operation.
How do I confirm whether this exhaust bellows fits?
Identify the sterndrive model, generation, serial number, and original bellows reference. Compare those details with the compatibility information on this page. If the original component is a universal-joint, shift-cable, water-intake, or exhaust-tube bellows, it is a different application and should not be substituted without verified fitment.
Is this an OEM component?
No. This listing is for an aftermarket replacement exhaust bellows. MerCruiser and other manufacturer numbers are provided only as reference numbers for identifying the intended application.
Are clamps and grounding clips included?
This listing is for one exhaust bellows. Package hardware may vary by supplier configuration, so verify the actual contents before beginning installation and obtain any required clamps or grounding clips specified by the service manual.
How often should exhaust bellows be inspected?
Inspect the bellows during routine annual service and whenever the sterndrive is removed. Replace it immediately if the rubber shows cracking, splitting, looseness, or other damage.
What shipping and warranty information applies?
Shipping options, delivery estimates, returns, and any applicable warranty are determined by the checkout and store policy for the order.
Safety and Important Information
- Verify the sterndrive model, generation, serial number, original part reference, and physical configuration before ordering.
- Do not use a universal-joint bellows, shift-cable bellows, water hose, or exhaust tube as a substitute for an exhaust bellows.
- Use the correct clamps and installation hardware for the specific sterndrive application.
- Follow the manufacturer's service manual, and use a qualified marine technician if you are not experienced with sterndrive removal and bellows installation.
About Sea Sierra
- Marine replacement parts selected for common service and repair applications.
- Clear reference information to help identify the correct component before ordering.
- Support for maintenance, replacement, and installation needs across popular marine systems.
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