16 VN 54 | APRIL – JUNE 2019
STRAIGHT FROM
THE TOP
First Line talks top strut
mount failure: the why,
the how, and the when.
Top strut mounts and bearings have evolved
from ‘Generation Ø’, featuring a simple steel
bearing in a steel beading, to ‘Generation 2.5’,
which uses a steel bearing with integral upper
spring and shock absorber support, made
from sophisticated, premium quality plastic
composites. Despite this transformation, top
strut mounts and bearings are still susceptible
to failure.
WHY DO THEY FAIL?
Common causes of failure include corrosion
from water, sand and salt on the roads,
fractures from poor road surfaces or accident/
collision damage, and brinelling from micro-
vibrations and incorrect hardening. Freezing
conditions combined with water penetration
cause additional problems by damaging the
bearings as well.
Some failures are linked to poor design,
forcing OE manufacturers to re-design and
upgrade them. On some vehicles however, it
can be the case that the top strut mount fails
prematurely, particularly with a number of
Fiat applications including the Fiorino/Qubo
(and their Citroën Nemo, Peugeot Bipper/
Tepee cousins), Doblo, Grande Punto and
Ducato.
HOW TO SPOT FAILURE
Spotting the failure should be relatively
straightforward. Failure can result in
increased noise – clunking, knocking, grinding
or creaking – particularly at low speeds, when
moving the steering from lock to lock on poor
road surfaces, as well as increased torque
on the steering wheel. Note that a faulty top
strut mount or bearing can affect the other
suspension components and will increase the
chance of their subsequent failure.
WHEN DO THEY NEED REPLACING?
Worn suspension components can increase
braking distance by 15% and vibration by
as much as 25%, making the vehicle much
less responsive. Therefore, it’s advisable
to replace them every 50,000 miles, or
whenever the shock absorber or coil spring
is changed.
As with any suspension work, these
components should be replaced in pairs. This
is a prudent policy not only because it’s more
economical for the owner, but it also avoids
inequality in the vehicle’s steering geometry.
WHY CHOOSE FIRST LINE?
For peace of mind, First Line top strut
mounts, bearings, and top strut mount kits
are made from premium quality components
to OE specifications and undergo stringent
examination, as well as detailed application
referencing, by the company’s highly qualified
product team.
Recent additions to First Line’s
comprehensive range of over 500 part
numbers, covering 94% of top 100 UK most
popular vehicles, include:
• FSM5487 - front top strut bearing L/R for
the Kia Sportage 2.0 (2010-16)
• FSM5485 - front top strut mount L/R for
Audi A3 1.4 (2014-17)
First Line top strut mounts and other
components are available from FPS for same/
next-day delivery. For more information,
speak to your local FPS representative.