If I knew then what I know now, I would have saved myself a lot of time, hassle
and money. I had been a bit disappointed by the harsh ‘gnashing’ noise coming
from the gearbox and had registered that fact through Piper Boats to Beta Marine
from the beginning (in August 2007). The noise was worst at normal canal
cruising speed but maybe having a Hospital silencer on the engine was allowing
me to hear the gearbox more? We agreed to wait and see if the noise would settle
down as the gearbox bedded in. As the noise only happened in forward gear I
triple checked that the direction of rotation, etc., was correct: it was.
Time went by and in 2008 we made the 600 mile circuit from Heritage Marina to
Gloucester, Bristol, London and back to Heritage. The mashing noise continued
unabated but I suppose we became used to it. The following year, while boating
in Holland, we began to hear (and feel) a peculiar thumping noise coming from
under the boards just after engaging forward gear before the engine was fully
warmed up. At this time the engine had run about 680 hours.
Investigation revealed that the engine was leaping about, but could be calmed
down by adjusting the throttle up or down for a few minutes and the problem
settled down once everything was up to temperature. On checking we found that
one of the engine mounts was loose (hidden under the engine frame) and there was
great jubilation, but that turned out to be a red herring (or should that be a
‘rood haaring’?) and the symptoms continued from time to time.
The problem did not always happen and was short lived each time. However, in the
spring of 2010, on a trip to Bugsworth with our Dutch friends, the morning
juddering became rapidly worse and was occurring again after the lunch stop.
Engine hours were now up to 860 and many theories were expounded by all and
sundry - could it be the stern tube bearing, the coupling, the drive plate or
the engine mounts? - but we really needed expert advice. After a little
persuasion Simon sent his man down for a diagnosis and he soon identified clutch
slip in the gearbox. He explained that Forewards and Reverse are selected by one
of two clutches and that one of these was wearing out - the ‘F’ word!
engine and gearbox assembly were still under the three year warranty period and
Beta agreed to replace the gearbox and in the end supplied the one which we had
seen on the stand at Crick!
Now, talking to various fleet engineers, it became apparent that our gearbox as
supplied is a PRM 120 ‘mechanical’ type and would not be suitable for hire fleet
or extended use. They would only use the PRM150 ‘Hydraulic’ version so I elected
to change to the latter and pay the difference. However it turned out more
expensive than expected because the hydraulic version also requires an oil
cooler, associated pipes and a new drive plate, all plus VAT.
So we set off from Heritage for our summer 2010 trip with our new gearbox
working fine and whizzed down the Severn from Stourport to Gloucester and on to
Sharpness with a noticeably quieter gearbox - in fact we could now hear water
sloshing around the weed hatch! Returning north I checked the gearbox oil (not
for the first time!) at Stratford and it looked like runny custard: the new oil
cooler had failed internally, mixing cooling water with the oil.
Within a couple of hours Beta had sent a man to replace it and change
the oil and we were away again: excellent service. Our next destination
was Trent lock at the junction of the rivers Trent and Soar to join the
Piper Summer Cruise, but just as we were descending Camp Hill locks we
learned that vandals had breached the Birmingham & Fazeley canal which
would be closed for (at least) a week, so we had to divert via Farmer’s
Bridge, Wolverhampton and Great Haywood. As we passed through
Burton-on-Trent a loud knocking began to occur between cruising speed
and tick-over speed which turned out to be a failing engine mount and
could be temporarily fixed by wrapping some thin rope around the mount.
Yet another call to Beta got the mounts changed under warranty again. It seems
that the original severe juddering of the engine assembly had given the mounts a
hard time although I hesitate to call it a ‘(k)nock-on’ effect.
Having subsequently cruised down the Trent and on to Boston and back it all
seems to be working satisfactorily but it was worrying to hear of similar
symptoms from some fellow Piper owners. As I said at the beginning, if I had
known what I know now about the different types of gearbox, I would certainly
not have specified the cheaper version, but that is hindsight
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