Trim Tilt Cylinder Repair Seal Kit – Fits OMC Cobra Stern Drive 2.3–8.2L & Volvo Penta SX Series (Replaces 0985060, 3854247)

Trim Tilt Cylinder Repair Seal Kit – Fits OMC Cobra Stern Drive 2.3–8.2L & Volvo Penta SX Series (Replaces 0985060, 3854247)

This aftermarket seal kit provides the necessary components to repair a leaking or failing trim and tilt cylinder. It is designed for a wide range of OMC Cobra Stern Drive models produced between 1986 and 1998 (2.3L to 8.2L engines) and also fits various Volvo Penta SX series drives.

This kit serves as a direct replacement for OEM part numbers, including OMC 0985060 and 0778202, Volvo Penta 3854247, and SeaSierra 0985060. Please verify compatibility with your specific engine model and existing part number before ordering.

• Installation: Designed for direct OEM replacement.
• Important Note: This kit contains parts to rebuild one cylinder. Two kits are required to service both port and starboard cylinders.
• Materials: Built to meet or exceed OEM specifications. Some sellers may offer variants with upgraded materials like Viton seals.

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.

OMC

Volvo Penta

Technical Specifications

Package Contents

1 x Seal Kit for a single trim/tilt cylinder.

Note: This kit contains all necessary seals to rebuild one cylinder. For servicing both cylinders, you will need to purchase two kits.

Installation Guide

1. Ensure the engine is off and the boat is properly secured on a trailer or lift.
2. Support the stern drive securely with a block or stand to prevent it from dropping unexpectedly.
3. Place a drain pan under the cylinder and disconnect the hydraulic lines. Be prepared for fluid to leak out.
4. Remove the upper and lower pivot pins or bolts that hold the cylinder in place.
5. Carefully remove the cylinder from the stern drive assembly for service.
6. Unscrew and remove the end cap from the cylinder body. This may require a specialized pin wrench.
7. Slide the piston and rod out of the cylinder body. Remove the old seals from both the piston and the end cap, noting their position and orientation.
8. Thoroughly clean all components and inspect the cylinder bore and rod for any scratches, scoring, or damage.
9. Carefully install the new seals onto the piston and end cap, ensuring they are seated correctly and not twisted.
10. Lubricate the new seals, piston, and the inside of the cylinder bore with fresh hydraulic trim fluid.
11. Reassemble the cylinder and reinstall it onto the stern drive by securing the pivot pins/bolts.
12. Reconnect the hydraulic lines, fill the trim fluid reservoir, and bleed the system according to your manufacturer's service manual to remove all air.

Troubleshooting & FAQ

Q: How do I know if this seal kit will fit my engine?
A: This kit is designed for OMC Cobra Stern Drives (2.3L–8.2L, 1986–1998) and various Volvo Penta SX series models. The best way to ensure a fit is to check the compatibility tables on this page and confirm that your existing part number matches one of the cross-reference numbers (OMC 0985060/0778202, Volvo Penta 3854247).

Q: How many kits do I need for a full repair?
A: This kit rebuilds a single trim or tilt cylinder. Most applications have two cylinders (port and starboard), so you will need to purchase two kits for a complete overhaul.

Q: What are signs that my trim cylinder seals are failing?
A: Common symptoms include visible hydraulic fluid leaking from the seals at the end of the cylinder, the stern drive slowly drifting down from a trimmed position over time, or a "spongy" and ineffective response when operating the trim controls.

Q: Some online reviews mention fitment issues. Is this kit reliable?
A: This is a high-quality aftermarket kit designed to meet OEM specifications. Fitment issues often arise from damage to the cylinder itself (like internal scoring or a bent rod) or improper installation. Always inspect the cylinder components for damage before rebuilding. Professional installation is recommended if you are not experienced with hydraulic repairs.

Q: OEM vs. Aftermarket?
A: 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.

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 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.