Upper Exhaust Bellows Kit for Mercruiser V6 & V8 Engines (2-Pack)
This upper exhaust bellows kit is anreplacement for Mercruiser V6 and V8 sterndrive engines from 1987 and newer using a center-mounted riser system. It creates a flexible seal between the exhaust riser and elbow, accommodating engine movement to prevent gas leaks and water intrusion. The bellows are made from a high-grade marine rubber compound with a 4-inch inner diameter, designed to withstand harsh marine environments.
This kit directly replaces Mercury/Mercruiser 32-44348T, Sierra 18-2748, GLM 89120, and Mallory 9-72805. It is compatible with a wide range of Alpha One (Gen I/II) and Bravo (I, II, III) sterndrive units.
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Fits Engine Models: For Mercruiser 4.3L V6, 5.0L V8, 5.7L V8, & 7.4L V8 engines (1987-2003) with center risers.
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OE Quality Aftermarket: Engineered to meet or exceed original equipment manufacturer specifications for fit and function.
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Complete Kit: Includes two (2) upper exhaust bellows and four (4) marine-grade stainless steel hose clamps for a full replacement.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM andbrands.
Brand |
Part Number |
Notes |
Mercury/Mercruiser |
32-44348T |
Supersedes part numbers 32-44348001 and 32-44348. |
Sierra Marine |
18-2748 |
Directreplacement. |
GLM Marine |
89120 |
Directreplacement. |
Mallory Marine |
9-72805 |
Directreplacement. |
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 |
Rated HP |
Stroke |
Years |
OEM Part No. |
Notes |
Mercruiser |
MCM 120 |
120 HP |
4-Stroke |
1987–2002 |
32-44348001 |
Center-mounted riser |
Mercruiser |
MCM 140 |
140 HP |
4-Stroke |
1987–2002 |
32-44348001 |
Center-mounted riser |
Mercruiser |
4.3L V6 |
175–220 HP |
4-Stroke |
1987–2003 |
32-44348T |
Alpha/Bravo compatible |
Mercruiser |
5.0L V8 |
230–260 HP |
4-Stroke |
1987–2003 |
32-44348T |
Small block Chevy |
Mercruiser |
5.7L V8 |
250–350 HP |
4-Stroke |
1987–2003 |
32-44348T |
Small block Chevy |
Mercruiser |
7.4L V8 |
330–454 HP |
4-Stroke |
1988–2001 |
32-44348T |
Big block Chevy |
Mercruiser |
Alpha One Gen I |
Various |
4-Stroke |
1983–1990 |
32-44348001 |
Sterndrive unit |
Mercruiser |
Alpha One Gen II |
Various |
4-Stroke |
1991–2003 |
32-44348T |
Sterndrive unit |
Mercruiser |
Bravo I |
Various |
4-Stroke |
1988–2003 |
32-44348T |
Sterndrive unit |
Mercruiser |
Bravo II |
Various |
4-Stroke |
1988–2003 |
32-44348T |
Sterndrive unit |
Mercruiser |
Bravo III |
Various |
4-Stroke |
1988–2003 |
32-44348T |
Sterndrive unit |
Technical Specifications
Specification |
Value |
Product Type |
Upper Exhaust Bellows Kit (2-Pack) |
Installation |
Center-mounted riser to exhaust elbow connection |
Housing Material |
High-grade marine rubber compound |
Housing Color |
Black |
Dimensions |
4" Inside Diameter × 4.25" Length (101.6mm × 108mm) |
Gross Weight |
862g (1.9 lbs) |
Package Dimensions |
13.5 cm × 24 cm × 16 cm |
Fitting Type |
Flexible bellows with hose clamp attachment |
Working Pressure |
Designed for marine exhaust system pressures |
Operating Temperature |
-40°F to 200°F (-40°C to 93°C) |
Warranty |
1 Year Limited Warranty |
Other Technical Attributes |
OE QualityReplacement, includes stainless steel clamps |
Package Contents
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2 x Upper Exhaust Bellows (Replaces OEM 32-44348T)
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4 x Stainless Steel Hose Clamps (Marine Grade)
Installation Guide
Professional installation is recommended. The following steps are a general guide:
- Ensure the engine is cool and disconnect the battery negative terminal for safety.
- Remove the engine cover and any access panels to gain clear access to the exhaust system.
- Visually inspect the exhaust riser and elbow for signs of corrosion, cracks, or damage. Replace any compromised components before proceeding.
- Thoroughly clean all mating surfaces to remove old gasket material and debris for a proper seal.
- To gain access, carefully remove the exhaust elbow, supporting its weight to avoid stress on other parts.
- Position the new bellow, ensuring it is correctly aligned with the riser and elbow without forcing it.
- Secure the bellow using the new stainless steel hose clamps. Tighten them to the manufacturer's specified torque to create a secure seal without damaging the rubber.
Troubleshooting & FAQ
Q: How do I confirm this bellows kit fits my engine?
A: This kit fits Mercruiser V6 and V8 engines from 1987 and newer that use a center-mounted exhaust riser system. The bellows has a 4-inch inner diameter. The best way to confirm is to match your old part number to one of the cross-reference numbers listed, such as Mercruiser 32-44348T, Sierra 18-2748, or GLM 89120.
Q: What are the common signs that my exhaust bellows needs replacement?
A: Look for visible cracks, swelling, or deterioration in the rubber. Other symptoms include the smell of exhaust fumes in the engine bay, water leaking into the bilge area from the exhaust, unusual engine noise, or a drop in engine performance.
Q: How often should I replace the exhaust bellows?
A: We recommend inspecting the bellows annually or every 100 hours of operation. Under typical conditions, a replacement is needed every 3-5 years. In saltwater environments, more frequent replacement may be necessary.
Q: OEM vs. Aftermarket?
A: This listing is anreplacement 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 anreplacement part and is not an OEM component.
- Professional installation is recommended to ensure safety and optimal performance.
Why Choose JLM MARINE?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.