Bellows Transom Repair Kit for Volvo Penta SX-C SX-M & OMC Cobra 1986–1998 (Replaces 3854127, 3852352, 3850426)

Professional Marine Bellows Replacement Kit

This is a complete transom seal bellows replacement kit designed for Volvo Penta SX series sterndrives (1994-1998) and OMC Cobra models (1986-1993). It provides all necessary components to restore the integrity of the transom seal, preventing water from entering the vessel and protecting critical driveline components. The bellows are constructed from a EPDM/Neoprene rubber compound for durability against UV, ozone, and saltwater exposure.

This kit serves as a direct replacement for multiple OEM andpart numbers, ensuring a precise fit for the specified engine models. It is engineered to meet or exceed original equipment specifications for sealing and performance.

• Complete Kit: Includes U-Joint bellows, exhaust bellows, water inlet hose, and a full sealing kit.
• Durable Construction: Made from high-grade EPDM/Neoprene rubber with stainless steel clamping hardware.
• Wide Compatibility: Fits a broad range of Volvo Penta SX, DP-S, DP-SM, and OMC Cobra/King Cobra sterndrives.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM andbrands.

Compatible Engine Models

Confirm your engine model/year in the table below.

OMC Cobra Series (1986–1993)

Volvo Penta SX Series (1994-1998)

Technical Specifications

Package Contents

This professional transom bellows repair kit is sold as a combination of one of each main component, and includes:

• ✅ 1x U-Joint Bellows Assembly (Replaces 3854127)
  • EPDM construction and stainless steel clamps included to protect the universal joint from water intrusion.
• ✅ 1x Water Inlet Hose (Replaces 3852352)
  • 1-inch diameter flexible hose made from high-temperature rated rubber with stainless steel clamps included.
• ✅ 1x Exhaust Bellows Assembly (Replaces 3850426)
  • Heavy-duty exhaust-rated material, 7-inch length with tapered ends, and corrosion-resistant clamp hardware.
• ✅ 1x Complete Sealing Kit
  • Includes marine-grade gaskets, O-rings, installation hardware, and bellows adhesive/sealant.
• ✅ 1x Installation Hardware Set
  • Includes all necessary stainless steel clamps (various sizes) and mounting hardware.

Installation Guide

Professional installation is highly recommended for safety and to ensure a proper seal. These are general steps and may vary based on your specific engine model.

1. Safety First: Disconnect the battery and ensure the sterndrive unit is securely supported before beginning work.
2. Remove Sterndrive: Detach the sterndrive unit from the transom assembly to gain access to the bellows.
3. Remove Old Bellows: Carefully cut and remove the old U-joint bellows, exhaust bellows, and water inlet hose. Note the orientation of each component.
4. Clean Surfaces: Thoroughly clean the mounting surfaces on both the transom and the sterndrive. Remove all old sealant, rubber, and corrosion.
5. Apply Adhesive: Apply a thin, even layer of bellows adhesive to the cleaned mounting surfaces where the new bellows will be seated.
6. Install New Bellows: Install the new bellows and hoses in the reverse order of removal. Ensure they are correctly seated and not twisted.
7. Secure Clamps: Position the stainless steel clamps correctly and tighten them securely to the manufacturer's torque specifications. This step is critical for a watertight seal.
8. Reinstall Sterndrive: Reattach the sterndrive, ensuring all connections are correct and secure. Install the new gaskets from the sealing kit as required.
9. Leak Check: Once assembled, lower the drive into the water and check carefully for any signs of leaks before starting the engine.

Troubleshooting & FAQ

Q: How can I confirm this kit will fit my specific engine?
A: The surest method is to match your existing part numbers to those listed in our cross-reference table. You can also use the "Compatible Engine Models" table to find your model and year. For final verification, contact us with your engine serial number.

Q: What are the signs that my bellows need to be replaced?
A: Common signs of failure include visible cracks or splits in the rubber, water in your bilge area, or a stiff or grinding noise when turning the sterndrive, which could indicate water has damaged the gimbal bearing or U-joints.

Q: How often should transom bellows be replaced?
A: Bellows are a routine maintenance item. The replacement interval can vary based on usage and water conditions (saltwater vs. freshwater), but a general recommendation is to inspect them annually and replace them every 3-5 years or at the first sign of wear.

Q: What is the difference between the U-joint bellows and the exhaust bellows?
A: The U-joint (or universal joint) bellows is the most critical, as it keeps water out of the gimbal housing and protects the U-joints and gimbal bearing. The exhaust bellows simply funnels engine exhaust through the sterndrive and into the water.

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?

• 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.