Fitment centre feature
Monroe: Technology
driven safety
Shock absorbers are often overlooked when
evaluating the safety or roadworthiness of a vehicle
because they cannot be easily seen, and are therefore
difficult to check for signs of damage or wear.
A
nd because they wear out gradually,
motorists often adjust unconsciously
to the change in their vehicles
handling, unaware that the efficiency of vital
components is compromised. It is therefore
essential that you check your customer’s
shocks for them and remind them how
dangerous worn shocks can be.
Although worn shock absorbers seriously
affect a vehicles handling and safety –
not all problems related to suspension
are necessarily caused by worn shock
absorbers.
Monroe South Africa offers the following
technical tips for fitment centres:
Steering wheel vibrations
This may not necessarily be from worn
or poorly fitted shock absorbers. Other
causes include: Poor wheel alignment,
poor wheel balancing, worn mountings,
worn suspension bushings, worn steering
dampers, unevenly worn brakes and even
problem tyres.
Shock rubber/bushing not
lasting
This could be caused by loose nuts, paint
not cleaned off threads before tightening,
incorrect sequence
or position of rubbers
during installation,
incorrect position or
omission of washers,
over-tightening of
mountings (not using
correct manufacturers torque spec)
or just that the rubbers have worn out
due to extreme terrain. In some cases
this may also lead to the damage of
the actual shock or vehicle suspension
mountings.
Oil Leakage
Although there is always the possibility
that the shock may have worn/faulty
seals, leakage is often caused by
piston rod damage during installation
(not using the correct tools); damaged
or missing dirt shields (particularly
if the vehicle is driven in a dusty
environment) accident or stone damage,
rod corrosion and faulty damaged or
missing protection kits. Always replace
the rubber boot and bump rubber
protection if it is showing any sign of
wear such as splitting or moving on the
piston rod. This will extend the life of the
shock.
Preventing the seal
from failing
Don’t forget to lower a vehicle
back onto its suspension
before finally tightening up. If a
telescopic shock is left hanging
while the vehicle is in the air
on a lift and it is then tightened
up at this point (particularly if it
is over-tightened) it can cause
the piston rod to operate at the
incorrect angle putting a side
force on the seal that can cause
it to fail.
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may 2014
Irregular and increased
tyre wear
This may not necessarily be from worn
shocks but can also be caused by incorrect
tyre pressure, incorrect wheel alignment,
faulty brakes or personal driving style. If
the tyre wear is in the centre of the tyre
the pressure is too high; if is on both outer
sides the pressure is too low; if it is only
on one side or feathered, the alignment or
balance may be out. If the wear is uneven
and patchy then the shocks may be worn.
Steering not centering
If the steering will not centre by itself this
could be caused by worn or damaged
shock mountings which can also be caused
by overtightening or using an airgun or
not tightening to the manufacturers torque
spec. This may also be accompanied by
poor handling and faulty suspension tester
readings often mistaken for worn shocks
Monroe shocks have a special “bleed
valve setting” built in to make it easier
for the installer to prime the shock before
fitting. If it is felt by hand it could lead to
the incorrect assumption that they are soft
or softer than other makes of shock.
Priming the shocks is essential to get the
oil flowing and valves working correctly
before the vehicle is driving, bearing in
mind that standard twin-tube shocks
cannot work effectively at angles greater
than 45 degrees, and that the shock has
been in a box on its side for months before
being sold.