Author Topic: Another Rudder Bearing Question  (Read 8641 times)

Trapeze Artist

  • First Mate
  • ***
  • Posts: 94
  • Karma: +0/-0
    • Little Hotels
  • Boat Model: Bavaria 30 Cruiser
  • Boat Year: 2005
Another Rudder Bearing Question
« on: June 10 2012, 23:40 »
Forgive me starting another thread on rudder bearings but I seem to have the opposite problem to most people. While there is a lot of discussion about tight bearings, I have a loose lower bearing on my 2005 30 Cruiser. I'm not sure what the rudder bearing setup looks like, but looking up from below there is a large white plastic piece that sits inside a tube in the hull. When I waggle the rudder side-to-side there appears to be about 1 to 1.5mm of play between the white plastic and the tube/housing. Is this piece of plastic a bush, or just some sort of shield? Should I be bothered by this much free play? Can I adjust it out? (One or two other posts suggested that it might be possible to tighten an adjuster nut on the top). I am due to go back in the water in a couple of days so time is tight if I am going to do anything before then.

KAOS

  • Second Mate
  • **
  • Posts: 43
  • Karma: +0/-0
  • Boat Model: BAVARIA 38
  • Boat Year: 1999
Re: Another Rudder Bearing Question
« Reply #1 on: June 10 2012, 23:59 »
 I would personally rather have  1mm of play than a very tight fit. Don.t forget that after some time the bearings swell in water Now... more than 1mm try to tighten the top nut by tiny weeny bit maybe a quarter to half turn.


russ

  • Swab
  • Posts: 20
  • Karma: +0/-0
  • Live the Dream
  • Boat Model: Bavaria 42 cruiser
  • Boat Year: 2006
Re: Another Rudder Bearing Question
« Reply #2 on: July 22 2012, 19:07 »
Ihave the same problem and my bushings make a banging sound when sailing in rough seas. I am in the process of replacing them.

Steve Cronin

  • Swab
  • Posts: 6
  • Karma: +0/-0
  • Boat Model: B42AC
  • Boat Year: 2001
Re: Another Rudder Bearing Question
« Reply #3 on: July 26 2012, 23:33 »
They are "self-aligning" bearings which consist of an outer housing into which sits a sperical inner of the same internal diameter as the external diameter of the rudderstock. However, on most Bavarias the rudderstock is stepped, having a different diameter where it mates with each of the bearings. Most of the Bavarias have both parts made of a nylon type material (various) but a few have the outer made of anodised aluminium (not good IMO). Any "play" can be eliminated by pre-tensioning these bearings by tightening the aluminium ring (after slackening the locking screw) at the top of the rudderstock by the use of a pin wrench. After doing this, it is important to monitor the tightness to ensure that it has not been overdone and slackening back as appropriate.

Steve Cronin


Nigel

  • R.I.P.
  • Old Salt
  • *****
  • Posts: 624
  • Karma: +0/-0
    • Dolcetto - My Boat
  • Boat Model: Bavaria 47
  • Boat Year: 2000
Re: Another Rudder Bearing Question
« Reply #4 on: July 27 2012, 13:35 »
... it is important to monitor the tightness to ensure that it has not been overdone and slackening back as appropriate.

It's also a good idea to mark the ring and the thread with a dab of paint.
Nigel Mercier: Forum Administrator

Steve Cronin

  • Swab
  • Posts: 6
  • Karma: +0/-0
  • Boat Model: B42AC
  • Boat Year: 2001
Re: Another Rudder Bearing Question
« Reply #5 on: July 30 2012, 09:58 »
... it is important to monitor the tightness to ensure that it has not been overdone and slackening back as appropriate.

It's also a good idea to mark the ring and the thread with a dab of paint.

Why? It has a locking screw which makes sure it can't move AND gives you a reference.

Steve Cronin


Nigel

  • R.I.P.
  • Old Salt
  • *****
  • Posts: 624
  • Karma: +0/-0
    • Dolcetto - My Boat
  • Boat Model: Bavaria 47
  • Boat Year: 2000
Re: Another Rudder Bearing Question
« Reply #6 on: August 01 2012, 23:01 »
... it is important to monitor the tightness to ensure that it has not been overdone and slackening back as appropriate.

It's also a good idea to mark the ring and the thread with a dab of paint.

Why? It has a locking screw which makes sure it can't move AND gives you a reference.

Steve Cronin

The locking screw doesn't always hold, I've seen this on several boats.
Nigel Mercier: Forum Administrator

Kerenza

  • Guest
Re: Another Rudder Bearing Question
« Reply #7 on: August 07 2012, 22:09 »
I have previously asked a similar question about wear in the rudder stock. My present theory is this.

When on the hard the rudder hangs from the (worn) top bearing showing sideways movement at the lower.
When in the water the rudder has positive buoyancy, pushing the rudder against the white plastic ring.
The top bearing then floats, on mine to the extent that water in the access hatch runs through the bearing and down the rudder stock, subsequently rusting the oil seal type  seal in the rubber tube.

If I could turn the adjusting collar I would try, but at the moment no amount of pressure will turn it, due I think to the locking screw having been tightened too much and the collar deformed where it is split.
If it would stop raining perhaps I could have a serious look at it.