Servicing your autopilot ram: The workshop’s recommendations

The diagnosis is simple: 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 autopilot ram is a wear part subjected to massive stresses. It absorbs tonnes of thrust with every wave. Yet it is often the most neglected component during winter layup.

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

1. The arch-nemesis: Salt on the rod

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

• The 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 mountings)

An autopilot that "knits" or overdraws is often a poorly mounted autopilot. 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.

• 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 rod end is worn or the mounting bolt is loose.

• ⚠️ Danger: 1 mm of play translates into violent shocks in rough seas, potentially ripping the mounting bracket clean off (we’ve seen it too often). Tighten or replace the rod ends immediately.

3. Hydraulics: Oil colour never lies

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 the weep.

• Colour: Oil should be clear and transparent.

  • Black oil? Seals are breaking down.

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

  • Action: In both cases, a full bleed 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 that drives the pump or the worm gear has brushes. When they wear out, the motor starts to misfire, then stops for good.

• Skysat tip: If your power unit is over 10 years old or has done a circumnavigation, dismantle 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), drive is often via an internal belt.

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

💬 Final word

A ram gives no warning before it fails—unless you know how to listen. A new noise, a squeak, or an oil stain are red flags.

Unsure about your ram’s health before the season? Don’t take the risk. Remove it and send it to our workshop. We run 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 the boat’s full-load displacement (everything included: crew, water, fuel, gear) and apply the following rule of thumb:

• Standard coastal cruising: 1 000 N per tonne of displacement at full load.
• Offshore racing / rough seas: move up to 1 500 N per tonne to absorb heavy rudder loads in big swell.
• Safety margin: choose the next size up if you are near the top of a category.

Raymarine types and Lecomble & Schmitt equivalents chart

Here are the three main classes in the pleasure-craft segment, 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 see one or more of these symptoms, your ram is working beyond its comfort zone. Check sizing first before replacing the autopilot control unit.

1. Ram overheating: after 30 minutes of steering at 15 knots, the ram is too hot to touch. Normal in heavy seas; abnormal in standard cruising.
2. Unusual motor noise: continuous hum, high-pitched whine under load. The DC motor is drawing beyond spec.
3. Slow response: the autopilot takes visibly more than 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 over 24 h where the datasheet lists 2–3 A. A shunt measurement confirms the diagnosis.
5. Rudder hunting: the boat oscillates side-to-side instead of holding a steady course, especially downwind. The autopilot is over-correcting late.

Field servicing

Quick reminders from the Skysat workshop:

• Visual inspection at every haul-out: leak-tightness, corrosion on mountings, rod-end play.
• Grease pivots and clevis with marine grease (e.g., Mobilgrease) 1–2 times per season.
• Check mounting torque on the rudder quadrant and clevis rod end with a torque wrench (follow manufacturer specs).
• Test maximum rudder angle in dry-dock, with quadrant freed: must reach 30–35° on each side without binding or clunking.
• Diagnose unusual noises: 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.