Lewmar 185TT Stern Adapter – 185mm (7-9/32") | 239-589310

Lewmar 185TT Stern Adapter

Part Number: 589310  |  SKU: 239-589310
Brand: Lewmar
Product Type: Stern Thruster Tunnel Adapter
Size: 185mm (7-9/32")
System: Stern Thruster Installation – Lewmar 185TT Series
Note: Stern Adapter only. Thruster unit not included.

Overview

The Lewmar 185TT Stern Adapter is the stern-end tunnel adapter component for Lewmar 185TT series thruster installations. Sized at 185mm (7-9/32") to match the 185TT tunnel specification, it provides the correct transom interface for mounting a Lewmar 185TT stern thruster. This adapter is sold separately from the thruster unit and must be used with the matching Lewmar 185TT tunnel and thruster for a complete installation.

Specifications

• Part Number: 589310
• SKU: 239-589310
• Tunnel Size: 185mm (7-9/32")
• Compatible Thruster Series: Lewmar 185TT
• Weight: Approx. 3.5 kg (estimated — confirm at time of delivery)
• System: Stern thruster tunnel installation
• Includes: Stern Adapter only — thruster unit, tunnel, and anode kit sold separately

Compatible Applications

• Lewmar 185TT Gen 2 Bow/Stern Thruster installations requiring a stern adapter at the 185mm tunnel size
• New installations and replacement of existing stern adapter in Lewmar 185TT series thruster systems
• Use only with Lewmar 185TT series thrusters and matching 185mm tunnel sections

Fitment Notice: Confirm your thruster series and tunnel tunnel diameter before ordering. Lewmar tunnel adapters are sized specifically to each thruster series — 185mm adapters are not interchangeable with other Lewmar tunnel sizes. Verify transoms clearance and tunnel opening dimensions before final installation.

Kit Contents

• Lewmar 185TT Stern Adapter (1 pc)
• Thruster unit, tunnel sections, and anode kit are sold separately

Installation Notes

1. Confirm the transom tunnel opening matches the 185mm (7-9/32") specification before cutting or drilling.
2. Install the stern adapter into the transom tunnel opening per the Lewmar 185TT installation manual.
3. Ensure proper alignment with the tunnel section and thruster unit prior to final securing.
4. Seal all penetrations per Lewmar’s installation instructions to prevent water ingress.
5. Install the matching anode kit on the thruster exterior to protect against galvanic corrosion.
6. Test the thruster for full range of thrust in both directions before returning to service.

Related Products

• Lewmar 185TT Gen 2 – 12V Bow Thruster 3.0kW (239-590006)
• Lewmar 185TT Gen 2 – 12V Bow Thruster 4.0kW (239-590008)
• Lewmar 185TT Gen 2 – 12V Bow Thruster 5.0kW (239-590010)
• Lewmar 185TT Gen 2 – 12V Bow Thruster 6.0kW (239-590012)
• Lewmar Tunnel 185mm (7-9/32") × 3’3" (239-589301)
• Lewmar Tunnel 185mm (7-9/32") × 4’11" (239-589302)
• Lewmar 185TT Anode Kit (239-589350)
• Lewmar 185TT Bow Thruster Zinc Anode – CMT-589350Z

Parts Desk Insights

Best Use Case: The Lewmar 185TT Stern Adapter is needed when installing a Lewmar 185TT series thruster at the stern of the vessel — it’s the critical interface piece between the hull/transom and the thruster unit. Most customers ordering this adapter are either completing a full stern thruster installation or replacing a damaged adapter on an existing system.

Common Questions: The most frequent issue is ordering the wrong adapter size — Lewmar thrusters come in multiple tunnel diameters and the adapter must match the thruster series exactly. Confirm your thruster’s model number and tunnel diameter (185mm for the 185TT) before ordering. Also confirm whether you need the tunnel section(s) as well as the adapter — both are required for a complete installation and are sold separately.