Lubricating a Linear Drive: Grease Points and Tips
Short answer: A linear drive autopilot has moving parts that need grease, mainly the ram, the pivot ends and, on some models, the clutch. The exact grease type and service interval are in the maker's manual, not in a listing. This site's listings state the drive type and whether a pack includes a drive; they do not state grease. For your boat, read the manual, ask the dealer, and use the maker's page to confirm the drive fits your steering.
What a linear drive is
A linear drive is an electric drive unit that pushes and pulls the boat's steering system in a straight line, instead of turning a wheel or spinning a rotary gear. Raymarine describes the drive unit as the part that interfaces with your vessel's steering system to keep you on the right course. On a sailboat with mechanical steering, a linear drive is a common choice. Raymarine's Type 1 Linear Drive Unit is described as a mechanical linear autopilot drive for boats up to 11,000 kg (24,000 lb) displacement.
The drive contains a motor, a reduction mechanism, and a ram or rod that extends and retracts. The ram is the moving part you can see, and it is the main part that needs grease. Listings name the drive type, so you know whether the unit in the box is a linear drive, a rotary drive, or a hydraulic pump. For a plain-language comparison of drive types, see the drive types explained article and the hydraulic versus linear drive comparison.
Why lubrication matters
The moving parts of a linear drive need grease to slide smoothly against each other. A dry ram or a dry pivot makes the mechanism work harder and can wear the seals that keep water and dirt out of the drive body.
The maker's manual names the lubrication points and the grease to use, and the service interval is set by the maker. This site does not publish its own grease recommendations. Listings state the drive type and the pack contents; they do not state grease. If you are planning regular upkeep, the maintenance schedule article explains what a routine looks like in general terms.
The catalogue also cannot tell you a grease type, a service interval or a torque figure. Those values are in the manual and on the maker's page. When a listing leaves a detail out, the missing detail is for the seller and the manufacturer to answer, not for the catalogue to invent.
Grease points on a linear drive
The lubrication points on a linear drive are the parts that move against each other. In general terms these are:
- The ram or rod where it passes through the drive body
- The pivot ends that attach to the steering system
- The clutch mechanism, on models that have one
- The protective boot or seal at the end of the ram
Where the details live
The exact points vary by model. In this site's catalogue, the drive unit is described by type and by the boat it fits, not by its grease points. The maker's page is the source for details. Inspecting the drive seals is a separate task; you can read more in the inspect drive seals article.
Use the grease the maker specifies, and use the amount the manual gives. Over-greasing can push grease past a seal. The manual tells you where to apply grease and where to leave it dry.
The recommended grease type and the service interval come from the maker's manual, not from a listing. The maker decides the grease that suits the materials in the drive. Ask the dealer or consult the manual before you buy grease.
The same advice applies to the clutch. Some drives have a manual clutch release, some release automatically. The manual explains what to lubricate and what not to lubricate. This site gives no installation instructions and no maintenance steps; a qualified installer or the maker's manual is the source.
If you are deciding whether to keep an existing drive or buy a new one, the retrofit considerations article covers that choice. If you are checking that a drive will fit your boat, the drive sizing article explains the buying side.
What to read before you buy
Before you buy, check whether the pack includes a drive. A core pack leaves the drive out, so you keep an existing drive or buy one separately. A complete pack includes the drive and the control head.
If you buy a new linear drive, note the model line and part number, and confirm with the maker's page what steering system it fits. The autopilot drive sizing article explains how to match a drive to a boat. Installation, including the first lubrication, is the maker's manual and a qualified installer's job. Plan for the manual to be your reference after the unit arrives.
An autopilot does not replace a lookout. The U.S. Coast Guard Boating Safety division reminds boaters that staying alert and keeping watch is part of operating a boat safely. That duty applies whether the autopilot is steering or not.
Lubrication and the rest of the system
The linear drive is the part that needs grease. The control head, the course computer and the heading sensor do not need grease; they are electronic modules. The rudder reference unit, where fitted, is a sensor, not a mechanical drive.
If the system is on a NMEA 2000 network, the cables and connectors are part of the installation. The NMEA 2000 standard describes a network for marine electronics; it does not specify lubrication. You can read about the network in the NMEA 2000 connectivity article.
The part that does require care is the drive's mechanical connection to the steering. That connection is where the grease points sit, and it is also where a misaligned drive can wear. The drive mounting position article covers alignment in general terms.
What to pick for your situation
| If you | Pick | Buying guide |
|---|---|---|
| You are choosing an autopilot that includes a linear drive | A complete pack listing | Best Complete Autopilot Packs (2026): 13 Picks Compared |
| Your boat already has a drive you plan to keep | A core pack listing | Best Autopilot Core Packs 2026: 12 Picks Compared |
| Your boat is a sailboat with mechanical steering | A sailboat autopilot guide | Best Sailboat Autopilots for 2026: 12 Picks Compared |
| You want a control head in the box | An autopilot with control head | Best Autopilot with Control Head (2026): 12 Picks Compared |
| You want a Raymarine Evolution system | The Raymarine autopilot guide | Best Raymarine Autopilot (2026): Marine Autopilot Reviews |
| You are shopping on a smaller budget | The small-budget autopilot guide | Marine Autopilot Under $2000: 4 Picks Compared |
Questions
Do I need to grease a linear drive autopilot?
Yes. The moving parts of a linear drive need grease to slide smoothly. The exact points and the grease type are in the maker's manual.
What grease do I use on a linear drive?
Use the grease the maker specifies. The manual names it, and an authorized dealer can tell you. This site does not state grease types.
How often do I grease the drive?
The service interval is in the maker's manual. The site does not publish intervals, because the maker decides the interval per model.
Can I install or lubricate the drive myself?
Installation and lubrication steps are the maker's manual's job, and a qualified installer is the right source for work on the boat. This article gives no steps.
What if my pack has no drive?
A core pack leaves the drive out. You keep an existing drive or buy a drive separately. A complete pack includes the drive.
Does an autopilot replace a lookout?
No. The U.S. Coast Guard Boating Safety division reminds boaters that keeping watch is part of safe operation. An autopilot is a steering aid, not a lookout.
Recent updates
- : First published.