Call Sign September 2011
Page 20
No! Contrary to the headline, this isn't a per-
An old worn-out rocker!
sonal attack on your younger life! Call Sign
was recently invited to Cricklewood Carriers, a
major taxi fleet operator and service garage in
north London to observe the much maligned
mum engine performance. Engines, we were
TX2 engine undergoing repairs to resolve that
told, run at very small tolerances throughout
familiar clattering noise of which many TX2
all their moving parts, usually with only frac-
owners will be aware...
tions of a millimetre to spare. The valves are
The problem in this case was speedily iden-
no exception, so everything has to be just
tified as worn valve rocker arms, causing the
right!
engine to run unevenly and reducing its effi-
With the central rocker shaft now complete-
ciency, together with high fuel consumption.
ly re-assembled with all new rocker arms, the
Firstly though, we should briefly explain the
task of refitting the parts to the engine began,
role of these valves and their rockers. Each of
ending only when the shaft had been careful-
the engine's four cylinders has two valves per
ly tightened down on its' securing bolts to the
cylinder, an inlet and an exhaust, allowing the
correct torque - that's tightness to you and me!
fuel/air mixture into the combustion chamber
Finally, all the pipes, wires and cables were
and then out again after the fuel is burned. It
gently put back in their place around the
is the rocker arms that pivot, literally rocking
engine bay and the ignition key turned on.
to and fro on a central shaft, opening and clos-
To Call Sign's amazement the engine fired
ing the inlet and exhaust valves at high speed
up immediately and was ghostly quiet com-
and at just the right time, allowing the engine
pared to the original clatter and hollow bop,
bop, bop noise when the cab drove into the
to run.
service bay.
So when these little rockers wear out, things
"I've done many of these valve replacement
start to go wrong - difficult starting, poor fuel
jobs over the years," John told Call Sign, "but
consumption, shakes and rattles. You proba-
All new replaced rockers
I've never seen parts as badly worn as these,"
bly get the picture...
he admitted, lifting small parts between his
The top of the engine was quickly disman-
everything attaches, was unbolted and put on
fingers to show our reporter. "It's astonishing
tled to reveal the inner workings of
the bench, before each individual rocker arm
the engine ran at all!"
Dagenham's finest! With the engine running at
was removed, inspected and then replaced on
A grin of satisfaction slowly spread across
idle, the offending worn parts were speedily
the shaft with a brand new rocker arm. John,
his face...
our engineer and guide, together with his col-
identified and the strip-down began in
leagues Tim and David, took great care to set
earnest.
© Call Sign Magazine MMX
everything up exactly as it should be for opti-
Firstly the central rocker shaft, upon which
Black cab support from the House of Lords!
Peer puts ORN case
for cabbies
In a House of Lords debate
prior to their summer recess,
Lord Bryan Davies of Oldham
recommended that London's
taxi drivers be allowed to use
the Olympic Route Networks
during next summer's London
EARLY TREATMENT MEANS SPEEDY RECOVERY
Olympic Games.
Treatment for pain & discomfort doesn't have to be expensive
The Labour Peer had taken part in
the debate regarding transport plans
The Centre offers fully qualified therapists in Physiotherapy,
for the 6 weeks of the Games and
Osteopathy, Sports Massage, Reflexology, Shiatsu, Remedial
Paralympic Games where he said that
Massage, Indian Head Massage, Hydrotherm, Massage Therapy,
black cabs should be permitted to
Acupuncture and Chinese Medicine.
use the controversial ORN lanes.
Lord Davies said that many years
Call us on 020 8507 8169
ago he had the "misfortune" of
or mobile 07973 639 473 for an early appointment
introducing the London bus lanes but
Email: andy@bptconline.co.uk or fax: 020 8507 9650
had left black cabs out of his proposi-
Out of hours enquiries welcome
tion!
"I still bear the scars to this very
Barking Physical Therapy Centre
day," he said with a smile, "so I warn
90 Longbridge Road, Barking, Essex, IG11 8SF
the Minister lest he should wish to
Opening Hours: Monday Friday 9am till 8pm and Saturday 9am till 2pm
bear such scars!"
www.bptconline.co.uk
