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Transom Seal Rebuild Kit – Fits Volvo Penta SX Stern Drives

Regular price $67.99

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Delivery and Shipping

Orders are typically processed within 1–2 business days.


U.S. orders usually arrive within 6–15 days, depending on stock location and destination.


International delivery times may vary due to customs processing.


Tracking information will be provided once your order ships.

If you have any questions, feel free to email us at info@seasierra.com, and we’ll get back to you within 20–36 hours.

Product Details

This Transom Seal Rebuild Kit – Fits Volvo Penta SX Stern Drives provides the essential components for servicing Volvo Penta SX series stern drives, including SX, SX-C, SX-M, and SX-R models. It is specifically not compatible with SX-A drives.

It serves as a direct interchange for Sierra 18-2772-1, Mallory 9-72931, and JLM Marine 17400-87L00.

  • Direct replacement installation simplifies maintenance.
  • Bellows are constructed from durable, marine-grade rubber/neoprene.
  • Engineered to meet or exceed original equipment manufacturer (OEM) specifications.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket suppliers.

Brand Part Number Notes
Volvo Penta 3853807 / 3841481 / 3850426 / 3852560 OEM part numbers for individual components in the kit.
Sierra 18-2772-1 Aftermarket Cross-Reference
Mallory 9-72931 Aftermarket Cross-Reference
JLM Marine 17400-87L00 Aftermarket Cross-Reference

Engine & Model Compatibility

Confirm your engine model in the table below.

For Volvo Penta engines, this kit fits the SX series models listed. Please verify that your drive is not an SX-A model, as this kit is not compatible.

Brand Model Associated Kit PN Notes
Volvo Penta SX 3853807 Gimbal bearing; Not compatible with SX-A drives
Volvo Penta SX-C 3841481 U-joint bellow
Volvo Penta SX-M 3850426 Exhaust bellow
Volvo Penta SX-R 3852560 Sealing kit

Technical Specs

Product Type
Transom Seal Kit / Bellows Kit
Installation
Direct replacement
Housing Material
Rubber/Neoprene (bellows)
Housing Color
Black
Warranty
Varies by manufacturer (typically 1 year)
Other Technical Attributes
Meets or exceeds OEM specifications

What’s in the Box

  • 1 x Gimbal bearing (Replaces OEM 3853807)
  • 1 x U-joint bellow (Replaces OEM 3841481)
  • 1 x Sealing kit (Replaces OEM 3852560)
  • 1 x Exhaust bellow (Replaces OEM 3850426)
  • 1 x Clamp

Installation Notes

  1. Ensure the engine is off and disconnect the battery for safety.
  2. Trim the stern drive to the full "up" or "trailer" position to access the bellows.
  3. Carefully remove the old exhaust bellow, U-joint bellow, and their associated clamps.
  4. Inspect the gimbal housing and remove the old gimbal bearing using an appropriate puller tool.
  5. Thoroughly clean all mating surfaces, removing any old sealant, corrosion, or debris.
  6. Install the new gimbal bearing squarely into the housing, ensuring it is properly seated.
  7. Fit the new U-joint and exhaust bellows, securing them with the new clamps provided.
  8. Confirm all components are securely fastened and properly aligned.
  9. Lower the drive and check for correct movement and ensure no components are binding.
  10. After launching the vessel, immediately check for any water leaks around the transom assembly.
  11. Professional installation is highly recommended for this component.

Troubleshooting & FAQ

Which Volvo Penta drives is this kit compatible with?

This kit is designed for Volvo Penta SX series stern drives, covering models SX, SX-C, SX-M, and SX-R.

Is this kit compatible with SX-A drives?

No, this kit is specifically not compatible with Volvo Penta SX-A drives. Ensure you have correctly identified your drive model before purchasing.

What are the signs my transom seal needs replacement?

Common signs of a failing transom seal include water leaking into the bilge area, visible cracks or dry rot on the rubber bellows, or a grinding noise from the gimbal bearing when turning the helm.

What are the main components included in this kit?

This kit includes the critical wear items for a transom service: one gimbal bearing, one U-joint bellow, one exhaust bellow, a sealing kit, and a clamp.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

  • Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
  • This is an aftermarket replacement, not an OEM component.
  • Professional installation is recommended for safety and performance.

About Sea Sierra

  • Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
  • Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
  • Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.

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