One GK24 I heard of regularly dried out at Itchenor, including resting on its rudder. Eventually the rudder broke.
Another problem that I only just heard of was the rudder fittings breaking off the rudder: the stainless steel strip either side of the rudder sheared at the lower fitting. Damage was reported to be due to fatigue. Fortunately the boat in question was near to help when it broke, but still caused concern to a passing tanker by apparently drifting towards it off St Helens.
I have also seen pictures of where a rudder had almost snapped
off just where the blade narrows to clear the skeg.
Probably a
grounding.
The GK24 uses nylon bushes between the pin and the bearings on the
rudder which wear out. When they do this the
rudder will touch the skeg and there will be a noticeable clunking
sound as the tiller is waggled. Replacements are still available
from Trafalgar Yacht Services.
As they are nylon, they tend to swell up with age and especially
with WD40. When I refitted Forethought's rudder, I had to shave
material off both the inside and the outside of the (original spares ?)
bushes before I could get the pin through or the bushes into the holes.
The tiller has a habit of rotting where it is clamped between the
stainless plates at the head of the rudder. Sitting on the tiller then
becomes an interesting experience (not me but another GK owner did this)