Bavaria 37 (2005) upper rudder bearing

Started by umu, December 04 2017, 11:42

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umu

I noticed a slight play (about 1-2 mm) in the rudder. It is visible on the upper section of the rudder shaft (the little square where the emergency tiller is mounted slightly moves by about 1-2mm on load changes when going thru larger swell). The lower bearing seems to have no play, checked the rudder on the hard.
Somehow I remember to have read that this can be adjusted by tightening the big nut on the top of the shaft. But looking at the Jefa drawings of the the whole setup (see attachment) I now don't get how this is supposed to affect play in any way, seems the rollers will just come out a bit lower when tightening this nut. Unfortunately I cannot just verify on the boat as it is 1500km away...

MarkTheBike

Hi Umu
I might be wrong but from your description this sounds more like loose cabling to the quadrant than rudder bearings. You didn't say if the play is lateral or rotational but if the bearings (top or bottom) are loose then you will get a side-to-side movement at the bottom of the rudder. Did you notice any when dried out? Have you checked for play in the chain, and cable tension from the wheel downwards? Unscrew and  remove (carefully!) the instrument panel in the binnacle which gives access to the drive cog on the wheel shaft. Access to the cable adjusters and quadrant is via the access hatch in the lazarette. Good luck...
ATB

Mark

umu

Hi Mark,
it is not the cabling - steering uses steering rods on this model.
The movement is lateral.
When under sail in larger swell I could actually see and feel a slight movement between the top rudder holding nut  and the bearing housing right below whenever the rudder got a load change due to crossing a wave.
There is no play sensible in the lower bearing - checked on the hard.

MarkTheBike

Hi Umu

OK, I see what you mean. As you say, it's difficult to see from the drawing what tightening up the top nut would achieve. However, (when you next get back there) giving the collar a 1/4 turn is easy enough and might have a good outcome, otherwise it sounds like a rudder-out job to check the bearing surfaces. If that's the case, I do remember one of the guys on here suggesting strapping an empty dumpy-bag to the sheet winches to catch an accidentally dropped rudder. Top Tip, that one...

cheers 
ATB

Mark

Spirit of Mary

Hi UMU, do you have the roller bearings? Because this is not the Bavaria standard. The standard is Delrin bush/ball which can adjust in an Aluminium housing. The rudder can be axially adjusted by the top nut. By doing this you can maybe reduce the lateral play. When you unscrew the small lockbold in the large cylindrical nut you can turn the nut clockwise and reduce the axial play in the rudder stock.  Turn the nut till you feel more resistance in turning the rudder. Than loose the  nut by turning 1/8 till 1/4 turn anti clockwise. Now lock the nut in this position by screwing /fastening the small bolt which squeezes the sliced large nut. If you are not strong enough with the original crosshead screw, replace it with an Allen screw/ internal hex screw. This can all be done while in the water. The rudder can't drop because the quadrant will prevent this and you don't need to unscrew the large nut.
Ger

umu

Currently I have the standard (original) bearings - but Jefa told me the construction of their bearings (apart from adding the needles on the shaft side) and measurements are 100% identical to the original ones, they can be 1:1 swapped.
However - before doing all this I want to make sure it is really required and not just an adjustment job that needs to be done.

I understand how the rudder is secured by the upper nut, how to take the rudder apart etc. - but I don't understand if (and how it works) the play could be reduced on this design by tightening the nut. So I'm wondering if the mentioned option of "adjustability" maybe only applicable to a different rudder design/vintage of Bavaria yachts or if I don't see the forest for the trees ??
It would be easy to check if the boat would be nearby, but it is 1500km away and next time I go it will be close to launching the boat so I want to make sure that I have the required parts if any and time/aid scheduled for the right job....

Moodymike

is it possible to overtighten the top nut and cause the steering to stiffen?

Spirit of Mary

Yes, see my earlier post reply. When this is the case loose the nut by 1/8 till 1/4 turn anti clockwise.