when is it time to replace rudder bearings?

[Monty]

re Hull 418, 2007 C350. I am seeking input on when it is time to replace the rudder bearings. I have about 1/4" side to side movement measured at the bottom of the rudder; two years ago at survey, the surveyor stated there was "some play but within acceptable limits". There is no forward/back movement, nor do I sense any vertical movement. There is no knocking when under way. There is a lot of input of when one should replace the bearings but its hard to find a consistent "this is when you do it". Warren has been a big help at Catalina but can't offer a hard and fast guideline. I would value input from this group. Many thanks, Steve

[MikeC]

I had about 1/4 inch side-to-side movement in my rudder bearing for several years without any problems. The movement got worse to the point that I could partially rotate the lower bearing where it slightly protrudes from the hull bottom (just above the rudder). I contacted Catalina and the person I spoke with (Warren) didn’t recommend replacing the bearing and instead recommended reseating it. I had the rudder dropped and the lower bearing was reseated using 3M 5200 sealant.

I haven’t had any problem since reseating the bearing. There is still slight (1/8-1/4 inch) side-to-side movement in the rudder when the boat is on land. But there is no vibration when underway. It’s also worth noting that there needs to be a slight gap between the rudder post and bearing so that water can lubricate it, and there needs to be enough clearance to allow for thermal expansion. Otherwise, the ability to turn the rudder back and forth could become very stiff.

I would think it’s time to at least reseat bearings if they obviously become loose or if you feel any significant vibration when underway. If upon removal the bearing is scored or shows other signs of damage then it should be replaced. The bearings aren’t cheap so I wouldn’t rush to replace them unless absolutely necessary. Also, to my knowledge you can’t buy a single bearing, but have to buy the complete set.

Hope this helps.

Mike
2008 Catalina 350, #456

[Monty]

Many thanks! Most helpful. Steve

[ccvalentino]

Hi Steve,

You’ll know when it’s time to address the rudder bearings. The thumping will get worse, to the point where it feels/sounds like the rudder is floating up in certain conditions. Typically is starts with thumping when you turn the rudder to its limits port and starboard.

With that said, it’s likely that you just need to rest the lower bearing. You can do this on the hard by lowering the rudder enough to drop the bearing. As I recall it’s set in 5200. I can dig up some info the Gerry Douglas sent me, when I was buying parts. In a bit shell. Don’t bay the kit and just rest the lower bearing first.

Chris

[Monty]

Thanks, Chris. We had a meeting of the "brain trust" of the yard's service staff and the conclusion was that I did not have an issue with the rudder bearing after all so we finished the running gear work and put her back in. Appreciate your help. Steve