How do I replace the saildrive seal on a Hallberg-Rassy 46?
I own a 1998 Hallberg-Rassy 46 with a Volvo Penta engine and a 120S saildrive. The rubber saildrive seal is now 8 years old and needs replacing before we head south. How do I actually get the drive apart and refit the new seal without pulling the whole engine out of the boat?
Answer
Replacing the Volvo Penta saildrive seal on an HR 46 requires disconnecting the engine and sliding it forward about 150 mm to allow the saildrive leg to tilt and lift clear of the hull. You will need a standard Volvo Penta saildrive seal kit (part number 21389074 for 120S, 130S, and 150S drives, costing around £250), an engine hoist or chain block, and a torque wrench.
Preparation and disconnection
Ensure the boat is securely propped ashore before working under the hull or shifting heavy engine weight. Start outside by draining the gear oil from the plug at the bottom of the saildrive leg. This releases about 2.5 to 3 litres of oil. Remove the folding propeller, the rope cutter if fitted, and the zinc ring anode.
Inside the walk-in engine room of the HR 46, isolate the engine. Shut the fuel valves and raw water seacock. Disconnect the exhaust hose, the raw water intake hose from the saildrive valve, the gear shift cable, and the main wiring harness plug. Undo the bolts securing the saildrive to the engine bell housing.
Moving the engine forward
The engine in a late-90s HR 46 is typically a Volvo Penta TMD31 or TMD22 weighing well over 250 kg. You do not need to lift it out of the boat, but you must support the rear end. Rig a chain block or come-along from a sturdy beam across the engine room hatch to take the weight.
- Unbolt the rear flexible engine mounts from the engine bed.
- Push or winch the engine forward by about 150 mm. You can usually slide it on its front mounts or block it up with timber.
- This creates the gap needed to pull the splined input shaft of the saildrive out of the engine flywheel damper plate.
With the engine clear, undo the bolts securing the heavy steel clamping ring that holds the rubber diaphragm to the hull bed. Lift the entire saildrive unit upwards and tilt it into the engine space. Pull the old rubber seal up and off the top of the saildrive leg.
Fitting the new seal
The fibreglass mounting flange on the hull must be spotless. Scrape away any salt, grit, or old adhesive with a plastic scraper. Wipe the surface with acetone. Any debris left here will cause a leak.