Servicing your autopilot ram: Skysat Workshop recommendations

Here’s the simple truth: your autopilot is your best crewmate. But its "brain" (the controller) is useless without its "muscle" (the ram).

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

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

1. The arch-enemy: salt on the shaft

This is the #1 cause of hydraulic leaks. Rams are often installed in a lazarette or sail locker—humid, salty environments. If salt crystallizes on the shaft (the chrome-plated piston that extends and retracts), these crystals act like sandpaper on the seals (lip seals) with every stroke.

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

• Never do this: Don’t grease the shaft with heavy grease—it will trap dust and salt. Use a dry PTFE (Teflon) spray or a lightly oiled cloth, nothing more.

2. Hunting for mechanical "play" (Swivel joints and fastenings)

An autopilot that "chatters" or overdraws power is often a poorly secured autopilot. The ram is connected to the rudder quadrant and the boat’s chassis via swivel joints (rose joints). Over time, these joints develop play.

• The test: Disengage the autopilot. Grab the ram body firmly and shake it side-to-side and up-and-down.

• The verdict: If you feel a "clack-clack", the joint is worn or the mounting bolt is loose.

• ⚠️ Danger: 1 mm of play turns into violent shocks in rough seas, risking support bracket failure (we’ve seen it too often). Tighten or replace the joints immediately.

3. Hydraulics: the oil color doesn’t lie

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

• Level: Ensure it’s 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? The seals are breaking down.

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

  • Action: In both cases, a full flush and seal replacement are required.

4. The blind spot: motor brushes

This is the "dumb" failure that often strikes after 3 000–4 000 hours of sailing. The electric motor driving the pump or worm gear has brushes. When they wear out, the motor starts misfiring, then stops altogether.

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

5. Clutch and belt (electro-mechanical rams)

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

• If the motor runs but the rudder doesn’t move (or slips) under load, don’t blame the controller: it’s usually a loose belt or a 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 the risk. 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 autopilot ram needs, start with the boat’s full-load displacement (total weight: crew, water, fuel, gear) and apply the following industry rule:

• 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 handle heavy rudder loads in big swells.
• Safety margin: choose the next size up if you’re near the top 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 for the 15–30 m segment, worth considering for heavy-displacement cruising sailboats.

5 signs of an undersized ram

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

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

Field servicing

Quick reminders from the Skysat workshop:

• Visual inspection at every haul-out: leak-tightness, corrosion on fastenings, joint play.
• Grease swivels and clevis pins with marine grease (e.g., Mobilgrease), 1–2 times per season.
• Check torque on the rudder quadrant and clevis joint with a torque wrench (manufacturer specs).
• Test maximum rudder angle in dry dock, free sector: should reach 30–35° on each side without binding or clunking.
• Diagnose unusual noise: disassemble the joint, inspect bronze bushings, replace preventively every 500 h of active piloting.

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