Rudder bearing replacement

Eventually, rudder bearings need to be replaced. Recently, I refit the bearings on my 1971 Swan 36, Freedom. I’ve owned Freedom for 22 years and this is the second set of bearings I’ve put on her rudder. I can tell when they need replacing because I can hear the rudder stock “clunk” in the gudgeon when she’s in any kind of a seaway. A look at this process demonstrates that rudder bearing replacement is something you can do yourself.

Essentially, the rudder is constructed of a 35mm (1 3/8”) stock to which two pintles are welded. Those pintles grasp the rudder blade on each side, with through-bolts. The entire assembly sits in and is supported by the gudgeon, which itself is through-bolted to the hull. There are three bearings (originally made of Delrin); one resides in the gudgeon, one in the lower part of the rudder tube, one in the upper part of the rudder tube.

I’d be willing to bet that other rudders are easier to deal with when it comes to bearing replacement. While the removal of Freedom’s rudder is fairly straightforward, the gudgeon is held captive by the balanced rudder blade — the leading edge of which extends forward of the stock under the gudgeon. As a result, to get the gudgeon off, and to remove/replace that bearing, the blade must be removed by grinding clear the pintles so that the through-bolts can be exposed and unscrewed.

The steps for this were as follows:

1. The two pieces of the quadrant were unbolted from the rudder stock, and the key removed from the keyway shaft.

2. The fairing around the gudgeon was ground away to expose the bolts, which were then removed and the rudder dropped. With Freedom, the total length of the rudder and stock was such that I did not need to dig a trench to lower it enough for the stock to clear the hull, though I know this is not the case with many boats.

3. The fairing on the rudder was ground away to expose the bolts on the pintles. As with the gudgeon, I had tightened those bolts (during the last bearing replacement) using an impact wrench, meaning that same tool was required to loosen them.

4. Once the pintle bolts were removed, the blade of the rudder slipped very neatly from them, and the gudgeon simply dropped off the shaft.

5. The stock, gudgeon, and old bearings were taken to a machine shop where the new bearings were created using a high abrasion-tolerant/low friction polyethylene called UHMW.

6. However, after cleaning the fairing from the stock, it was noticed that the pintles suffered from some crevice corrosion, which could have compromised their strength. As a result, the assembly was brought to a stainless welder, who removed the old pintles and welded on new ones, with some added reinforcement. This was a job that required several tries, as there is very little clearance on Freedom for the rudder both in terms of its swing, and the spaces between the top of the rudder and the hull, and where the balanced section of the blade clears the gudgeon.

7. Reassembly of the rudder was basically the reverse of the above, with the first step being the insertion of the gudgeon bearing in, then the gudgeon itself being slid onto the end of the shaft. Next, the pintles were bolted to the blade and faired. I’ve always had a hard time getting West System epoxy to “stick” to stainless, so for the first layer of fairing I used Interlux’s InterProtect Watertite epoxy, which seems to be very tenacious. After that, all the fairing was done with West System epoxy, using their 410 additive to create an easily sanded fairing surface.

8. Sanding and painting followed, as well as the two bearings being installed in the rudder tube.

9. Lastly, the rudder was simply pushed back up into the boat, the gudgeon bolted through, faired over, and the quadrant reattached.

Dropping a rudder to repair it, or any of its attendant parts and pieces, may sound like a huge job, but it isn’t necessarily so. Like many do-it-yourself boat projects, it’s a matter of thinking the process through, and moving ahead with (sometimes feigned!) confidence. There’s no doubt you’ll get to know your boat better once you’re done.

Peter Stoops is the owner of Freedom and an owner of Chase a Swan 40 on which he has made multiple Atlantic crossings. Stoops lives in Maine and runs a software company when not sailing.

By Ocean Navigator