How do I replace the saildrive seal on a Hallberg-Rassy 37?
I need to change the saildrive diaphragm on my 2005 Hallberg-Rassy 37. It's got the original Volvo Penta D2-55 and a 130S drive. The seal is now ten years old, so I'm doing it this winter on the hard. What is the actual step-by-step process for getting the drive out and the new seal in?
Answer
To replace the saildrive seal on a Hallberg-Rassy 37, you must slide the Volvo Penta D2-55 engine forward, unbolt the clamping ring and split the upper gear housing from the lower leg to swap the rubber diaphragm. This heavy job requires a clean working environment and a calibrated torque wrench to ensure the new seal seats perfectly without leaking.
Shifting the Engine
Start on the hardstanding by draining the saildrive oil from the bottom plug and removing the propeller. Inside the engine bay, you must create enough room to pull the saildrive shaft out of the vibration damper. On the HR 37, this means sliding the D2-55 forward by 15 to 20 centimetres.
Mark the exact position of the engine mounts on the beds with a marker pen before unbolting anything to save an alignment headache later. Disconnect the raw water intake, exhaust hose, gear shift cable and any wiring looms or fuel lines lacking slack. Support the rear of the engine using a small block and tackle attached to a strong point above, or block it up with timber from below. Lash the block securely so it cannot slide back and crush your hands. Unbolt the engine mounts from the beds and slide the unit forward.
Extracting the Saildrive Leg
With the engine moved, remove the bolts securing the saildrive upper housing to the bell housing. Undo the ring of bolts securing the steel clamping ring that holds the rubber diaphragm down to the fibreglass engine bed. Lift the clamping ring away.
You do not drop the saildrive out of the bottom of the hull. Instead, undo the bolts joining the upper gear housing to the lower leg. Lift the upper gear housing away and set it on a clean rag. You can now pull the lower leg straight up and into the cabin. The unit weighs around 30 kilograms, so ask a second person to help you lift it clear.
Fitting the New Diaphragm
A genuine Volvo Penta seal kit for the 130S drive (part number 21389074) costs around £250. The box includes the main rubber diaphragm, the external hull fairing flap and the necessary O-rings. Slide the old seal off the top of the lower leg. Inspect the aluminium mating surfaces where the upper and lower housings meet. Clean off any old salt or corrosion using a plastic scraper or 800-grit wet-and-dry paper. Be careful not to score the soft aluminium.