Replacing rudder bushes
The new bush in place, but
with the stock not yet aligned
Collar, saddle and emergency tiller fittingThe final fitting completedI offered them up to see that they
fitted. If they were a tight fit they
would contract once they were
driven home, and this would
interfere with the fit of the rudder
stock. If they were loose, then
that could be a problem. The
hope was to find that all was
well, replace all the bearings,
apply some gentle lubricant to
the rudder stock and, with some
help, replace the rudder.
The bearings are not nylon,
as it swells in water and could
possibly seize up the rudder
stock. Although no specification
was given – other than ‘made to
Westerly specifications’ – they
appeared to be acetal (sometimes
sold as Delrin), which is what
I would have chosen were I to
have had them made up.
Modifying the
new bearings
Preparation for raising the rudder
again was at least as important as
lowering it. Because the bottom
bearing was loose, lowering the
rudder wasn’t obstructed by tight
bearing clearances. Things could
have happened in a bit of a rush,
but some care was taken to
prevent that. When replacing the
rudder, difficulties arose because
the bearings were oversize, and
the rudder was difficult to align
because lifting the rudder out of
its pit in the ground was initially
difficult – until a friend turned up
with some ratchet luggage ties
which gave us better leverage.
The top bearing was around 3mm
over size, and without a lathe it
was only possible to grind the
excess away. These bearings are
naturally slippery but hard, almost
like bronze, and grinding is a slow
process which includes frequent
visits to the boat itself, climbing up
the ladder, distributing more clay
around the cabin and trying the
bearing for size. At the end of day
one, this had been achieved.
Once everything finally fitted
after considerable resizing of the
bearings, I replaced everything at
the top end in reverse order.
On day two, the lower bush was
inserted into the lower end of the
rudder tube, and found to be a
good fit. It was removed and tried
on the rudder stock, with the
assistance of a wooden block. It
was a good push-fit. But when
the bush was pushed home into
the rudder tube and the rudder
offered up, it would not fit.
Problems with alignment were
blamed. The process was
modified by putting the bearing on
to the stock, and offering up the
rudder again so that alignment
was more manageable. The stock
went in only as far as the top
of the lower bearing, and then
wouldn’t go any further. We jacked
the rudder up with some force
but found that not only was the
bearing starting to bulge, but we
had lifted the back end of the boat
a few millimetres, which isn’t a
good thing. When we removed
the rudder yet again, the bearing
was clearly too large for the tube.
What seems to have happened
is that in trying the bush on the
rudder stock with the assistance
of a wooden block it had
expanded enough to causeinterference. This
had to be ground
down to fit.
On the third
day, using some
webbing straps
(of the kind used
for holding down
things on roof racks
or trailers) to help
raise the rudder again,
the process took less than
an hour. A new parallel key
had been cut and filed and
the quadrant was refitted over
this. The key must be made of
key steel, not mild steel. If you
know the size, one can be
ordered online.Final fitting
There was still one snag. The
rudder is prevented from falling
out of the boat by a substantial
stainless steel collar with a
through bolt at the top of the
stock. The new bushes were
slightly oversized and the plastic
collars that prevent the bushes
slipping up or down the tube
needed adjustment. Fortunately
the amount needed was small,
and by firming up the bolts of the
saddle and lightly sanding off the
surface of the flat thrust bearing at
the top, the bolt could be inserted
through the collar.
The final fitting completed,
the steering was swung side to
side several times to check it,and the cable tension rechecked.
This is a job that could take four
or five hours from start to finish,
but in the case of our rudder,
it took three days: a basic
8.30-9.00 start to a 3.30 finish
on winter days, with some
comfortable coffee breaks
and the generous assistance
of two others.
Problems were down to two
things – in particular the size
of the bearings supplied, and
to a lesser extent the alignment of
the rudder stock when refitting it –
simply because getting a line
under the centre of gravity of
the rudder was difficult. But once
the rudder was high enough to
get the hydraulic jack under it, the
job was easy, and made a bit
easier by the fact that the bottom
of the rudder is flat. A rudder
with more profiling to it might
be a little more difficult.