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DAYCO DAMPER PULLEYS
Dayco, a leading
engine products
and drive systems
supplier for
the automotive,
industrial and aftermarket
industries, is also a major
player in the production of
original equipment (OE)
torsional vibration dampers,
which it manufactures
for many prominent vehicle
manufacturers, both
automotive and heavy-duty,
across Europe and around
the world.
Modern powerplants are
highly engineered to deliver
the optimum combination
of power and torque, alongside
fuel efficiency and minimal
exhaust emissions. This
objective often comes at the
cost of high levels of engine
vibration, which is generally
intensified by the significant
pressures present in the
engine’s combustion chambers,
an occurrence especially
prevalent with diesel
units.
This vibration is transmitted
through the crankshaft
and therefore has a significant
impact on the engine’s
power transmission drive
systems. To reduce this
problem, Dayco engineers
have developed a range of
damper pulleys, with the
prefix DPV.
Generally installed directly
to the crankshaft, the
damper reduces the circular
vibrations that cause the
primary problem, decreasing
wear on many of the
engine’s components. Naturally,
the front end auxiliary
drive (FEAD) system is a
principal beneficiary, which
increases the durability of
the entire powerplant, but
they also improve comfort
for the vehicle’s occupants.
There are three types of
damper that, depending on
the application, are generally
installed: the simple,
double and decoupler.
The simple damper is integrated
within the FEAD
system, its single rubber element
provides sufficient vibration
reduction for applications
with standard NVH
(noise, vibration and harshness)
requirements.
The double damper encompasses
two rubber elements
within its metal
parts, which are designed to
absorb vibration at different
frequencies, and is for use
in applications that generate
high power and increased
vibration, such as modern
diesel engines.
Although the decoupler
damper still incorporates
a rubber ring, the damping
function is carried
out through metal
springs, as opposed
to solely relying
on its rubber element. It is
used on the latest generation
engines with greater power
and enables the FEAD system
to cope with high mileage
and adverse conditions,
particularly for applications
that feature a BSG (belt start
generator) function for their
start/stop systems.
Damper Replacement
Naturally, as with every
wearing part, over the
course of time and as the
vehicle’s mileage increases,
problems can occur and
the damper can lose its efficiency
or sometimes even
break, which itself obviously
increases the risk of failure
in other parts of the engine’s
drive systems.
To avoid these problems,
dampers should be checked
for signs of wear, such as abnormal
noises, unpleasant
vibrations, at every 40,000
mile interval or when replacing
the auxiliary belt. However,
as a matter of course
and irrespective of the signs,
Dayco suggests they are
changed every time the timing
belt is renewed.
Technicians must be aware
however, that in order to
check the damper correctly,
it needs to be removed from
the engine because the back,
as well as the front needs
to be examined to fully assess
its condition. In addition,
whether it needs to be
replaced or not, if its fixing
bolts are designed to stretch
on initial fitment, these must
be changed, as they will no
longer meet their design
tolerances if reused.
24 News.indd 1 27/08/2019 10:20