How do I replace the cutless bearing on a Hallberg-Rassy 37?
I have a 2005 Hallberg-Rassy 37 with a Volvo Penta D2-55. The cutless bearing has a lot of play, but there is a large skeg right behind the prop. How on earth do I get the old bearing out and a new one in without removing the rudder?
Answer
To replace the cutless bearing on a Hallberg-Rassy 37 without dropping the skeg-hung rudder, you must use a specialised bearing puller to draw the old shell out over the prop shaft. Expect to fit a standard 30mm internal diameter brass-shelled nitrile bearing, which typically costs around £45 to £60.
Removing the Propeller
The HR 37 features a substantial skeg immediately aft of the propeller. This blocks the 30mm stainless steel shaft from sliding out backwards. You must extract the bearing over the shaft while it remains coupled to the engine.
Start by removing the propeller. For a fixed bronze prop, remove the split pin and shaft nut before using a heavy three-leg puller to break the taper. For a folding propeller like a Flexofold or Gori, dismantle the blades using the correct Allen keys. Remove the locking nut and pull the hub. Leave the shaft key safely to one side so it avoids the boatyard gravel.
Extracting the Old Bearing
Look closely at the sides of the bronze P bracket for two retaining grub screws. Layers of old antifouling usually hide them. Dig out the hex heads with a sharp pick so your Allen key seats fully. This prevents rounded heads. Remove both screws completely.
Because the shaft blocks the exit, you cannot use a simple drift to knock the bearing out. You must press it out. A commercial tool like a Strut Pro is ideal but expensive. You can build a homemade puller using a length of M10 high-tensile threaded rod, heavy steel washers and a piece of steel pipe with an internal diameter slightly larger than 45mm to act as a receiver. You also need two half-moon steel pushers that fit around the 30mm shaft to press against the forward edge of the brass bearing shell.
Never stand directly beneath a heavily tensioned puller tool. Components cause serious injury if a thread strips under load. Apply tension evenly. If the bearing seizes solid, uncouple the shaft from the gearbox and slide it aft until it touches the skeg. Carefully run a hacksaw blade inside the bearing to cut a slit through the brass shell. This relieves the tension.