There is a fault in the design of the steering axle of the Dufour 40 (2004) this same kind of design is used on some Bavarias also I think. The self-aligning plastic bearings can bend out of shape due to cumulating aluminium oxide and/or calcium. This will freeze up the steering. This was the case with our boat. We first noticed the problem when we picked up the boat from the seller, Essex Boatyards ltd. During the crossing of the north sea, the steering proved out to be unbearably stiff. In the end we had to change the helmsman every 10 minutes just to keep going. We hauled the boat out of the water at Ijmuiden and had the lower bearing burred bigger. This loosened the steering so we could continue towards Finland, but left a small lateral play in the rudder, which manifested as tremble in faster speeds. So we had to change the lower bearing during the next winter. And to those interested: No, Essex Boatyards did not think that this was a problem they should have noticed or corrected before selling us the boat, so the expences are on us.
How to change the bearings for the steering axle in a dufour 40.
1. Take the quadrant off and lower the blade to the ground. You need at least 69cm of free space below the rudder blade to get it out. The Bolt that goes through the quadrant is stainless steel and the quadrant is aluminium, so anticipate problems. We had to cut the bolt and burr the bolt out. I had stainless steel spacers installed for the hole to prevent the bolt from seizing up in the future (see pic. below)
After removing the blade, you’ll have to remove the lower bearing. To do so, you’ll have to brake it (without damaging the aluminium casing). First saw with a steel saw two adjacent grooves
With a small chisel (e.g. 8mm) carefully chip away the plastic between the just-made-grooves.
After a while the bearing should brake free, at least after you’ve cut it completely. Turn the bearing and pull it out.
Grind and polish the casing with a nylon brush, try to get it as smooth as possible.
Place the new bearings (order from your Dufour importer) and re-assemby the whole system. There you have it. With the right tools this takes about 1 to 1.5h.