Rudder ram maintenance: Skysat workshop recommendations

Bottom line: your autopilot is your best crewmate. But its "brain" (the control unit) is useless without its "muscle" (the ram).

Whether hydraulic (Lecomble & Schmitt, Hypro) or electro-mechanical (Raymarine Type 1/2, Jefa), the rudder ram is a wear part subjected to extreme stress. It absorbs tonnes of thrust with every wave. Yet it is often the most neglected element during winter lay-up.

Here is the checklist our technicians use to avoid ending up at the helm in the middle of the Bay of Biscay.

1. The main culprit: salt on the rod

Salt crystallization on the rod (the chrome-plated piston that extends and retracts) is the #1 cause of hydraulic leaks. The ram is often installed in a stern locker or sail locker—humid, salty environments. These crystals act like sandpaper on the seals (lip seals) with every movement.

• Expert move: Rinse the rod with fresh water regularly. Wipe it with a clean cloth.

• Do not: Do not grease the rod with heavy grease that will trap dust and salt. Use a dry PTFE spray or a lightly oiled cloth—nothing more.

2. Hunting for mechanical play (rod ends and fasteners)

An autopilot that "knits" or overconsumes often has loose mounting. The ram is connected to the rudder quadrant and the boat’s chassis via rod ends (rose joints). Over time, these rod ends develop play.

• Test: Disengage the autopilot. Grab the ram body firmly and shake it laterally and vertically.

• Verdict: If you feel a "clack-clack", the rod end is worn or the mounting bolt is loose.

• ⚠️ Danger: Even 1 mm of play translates into violent shocks in rough seas, potentially leading to support bracket failure (we’ve seen it too often). Tighten or replace rod ends immediately.

3. Hydraulics: oil color doesn’t lie

If you have a hydraulic ram, check the reservoir (integrated or remote).

• Level: Ensure it is between min and max. A drop in level always indicates a leak. Run a paper towel under the fittings to locate seepage.

• Color: Oil should be clear and transparent.

  • Black oil? Seals are breaking down.

  • "Mayonnaise" oil? Water has entered the circuit.

  • Action: In both cases, a complete bleed and seal replacement are required.

4. The blind spot: motor brushes

This is the "dumb" failure that often occurs after 3,000–4,000 hours of sailing. The electric motor driving the pump or worm gear has brushes. When worn, the motor starts to misfire, then stops completely.

• Skysat tip: If your power unit is over 10 years old or has done a circumnavigation, remove the motor to inspect brush length. Lots of black dust inside? Time to replace them (maintenance kit available).

5. Clutch and belt (mechanical rams)

On electro-mechanical rams (e.g., Raymarine), power is often transmitted via an internal belt.

• If you hear the motor running but the rudder doesn’t move (or slips) under load, don’t blame the control unit: it’s usually a loose belt or worn clutch.

💬 Final word

A ram doesn’t warn you before it fails—unless you know how to listen. A new noise, a squeak, or an oil stain are warning signals.

Unsure about your ram’s condition before the season? Don’t take risks. Remove it and send it to our workshop. We perform a full bench test (pressure, leak-tightness, power draw) to validate its reliability.

Sizing: the 1,000 N per tonne rule

To estimate the minimum thrust force your ram needs, start with your boat’s full-load displacement (total weight: crew, water, fuel, equipment) and apply the following rule of thumb:

• Standard coastal cruising: 1,000 N per tonne of displacement at full load.
• Offshore racing / rough seas: increase to 1,500 N per tonne to absorb heavy rudder loads in big swells.
• Safety margin: choose the next size up if you’re at the upper limit of a category.

Raymarine type chart and Lecomble & Schmitt equivalents

Here are the three main recreational segments, with L&S equivalents and useful strokes. Sources: Raymarine Pilot Selection Guide 2026 and Lecomble & Schmitt distributor 2026.

Note: Brands Hypro and Jefa offer alternative hydraulic rams in the 15–30 m segment, worth considering for heavy-displacement cruising sailboats.

5 signs of an undersized ram

If you notice one or more of these symptoms, your ram is struggling beyond its comfort zone. First check sizing before replacing the autopilot control unit.

1. Ram overheating: after 30 minutes at the helm in 15 knots, the ram becomes too hot to touch. Normal in heavy weather; abnormal in standard cruising.
2. Unusual motor noise: continuous humming or high-pitched whine under load. The DC motor is running beyond specs.
3. Degraded response time: the autopilot takes over half a second to react to a helm command. Lag is felt at the wheel.
4. Abnormal power draw: the autopilot draws 6–8 A on average over 24 h where the datasheet shows 2–3 A. A shunt measurement confirms the diagnosis.
5. Rudder hunting: the boat oscillates on either side of course instead of holding a steady heading, especially downwind. The autopilot is late to correct.

Field maintenance

Quick reminders from the Skysat workshop:

• Visual inspection at every haul-out: leak-tightness, corrosion on fasteners, rod-end play.
• Grease axles and clevis with marine grease (e.g., Mobilgrease), 1–2 times per season.
• Check torque on the rudder quadrant and clevis rod end using a torque wrench (follow manufacturer specs).
• Test maximum rudder angle in dry dock, with quadrant freed: should reach 30–35° on each side without binding or clunking.
• Diagnose unusual noise: remove the rod end, inspect bronze bushings, replace preventively every 500 hours of autopilot use.

Skysat distributes Raymarine and Lecomble & Schmitt. This article reflects our experience installing and servicing autopilots on sailboats from 8 to 22 m since 2002.