Transom Seal Bellows Kit – Fits Volvo Penta SX/DP & OMC Cobra Stern Drives (Replaces 3854127)

Transom Seal Bellows Kit – Fits Volvo Penta SX/DP & OMC Cobra Stern Drives (Replaces 3854127)

This transom seal bellows kit is designed for Volvo Penta SX and DP series stern drives (SX-S, SX-C, SX-R, SX-M, DP-S) and OMC Cobra stern drives from 1986–1993. It is a direct replacement for models that do not use a cone clutch, ensuring a precise fit and reliable performance.

Manufactured to meet or exceed OEM specifications, this kit is produced in an ISO9002 certified facility using the same high-quality, marine-grade rubber as original parts. It provides a durable seal to protect critical transom components from water intrusion.

• Installation Method: Direct replacement with clamp-on fitting.
• Core Component: Includes one U-Joint bellows with a corresponding clamp.
• Housing Material: Built with durable, marine-grade rubber for longevity.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below.

Volvo Penta

OMC (Johnson/Evinrude)

Technical Specifications

Installation Guide

1. Safety First: Disconnect the boat's battery before beginning work.
2. Remove Stern Drive: Carefully detach the stern drive unit from the transom assembly to access the bellows.
3. Access Old Bellows: Locate the old U-joint bellows connecting the transom plate and the drive.
4. Remove Clamps: Loosen and remove the clamps securing the old bellows at both ends.
5. Remove Bellows: Carefully pull the old, cracked, or worn bellows off the mounting rings.
6. Clean Surfaces: Thoroughly clean the mounting surfaces on the transom and drive to ensure a clean, debris-free seal.
7. Position New Bellows: Slide the new bellows into position, ensuring it is properly seated on both ends.
8. Secure Clamps: Install and tighten the new clamps to secure the bellows. Do not overtighten.
9. Reinstall Stern Drive: Re-attach the stern drive unit to the transom assembly.
10. Check for Leaks: After reassembly, lower the drive into the water and check carefully for any signs of leaks around the new seal.

Troubleshooting & FAQ

How do I confirm this kit fits my specific stern drive?
Verify your drive's model (e.g., SX-M, DP-S, or Cobra) and year. This kit fits Volvo Penta SX/DP drives without a cone clutch and OMC Cobra drives made between 1986 and 1993. Cross-reference your existing part number with the numbers listed in our table to ensure compatibility.

What are the common signs that my transom bellows needs replacement?
Visible signs include cracks, splits, or perishing rubber on the bellows. Functionally, water leaking into the bilge area is a critical indicator that the bellows has failed and requires immediate replacement to prevent severe damage to the U-joint and gimbal bearing.

How often should I replace the transom U-joint bellows?
It is recommended to inspect the bellows annually as part of your regular maintenance schedule. As a preventative measure, most technicians recommend replacing them every 3-5 years, depending on usage (saltwater vs. freshwater) and storage conditions.

OEM vs. Aftermarket?
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.

How fast do you ship and how much does it cost?
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.

What is your warranty and return policy?
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.