A trailing arm is a suspension link that is attached to the chassis at a point forward of the axle.
Many suspension systems have one or more such arms. If the primary structural attachment is a
trailing arm, then it is typically called a trailing arm suspension. The typical setup is an arm
attached to the chassis with a pivot that has it’s axis Across the chassis side to side.
The trailing arm is the piece of the suspension system that connects the vehicle’s axle to its
chassis. In addition to the trailing arm itself are the trailing arm bushings. These are rubber or
polyurethane components that act as cushions and reduce friction between the suspension
parts.
The purpose of a trailing arm is to locate and control the movement of the rear axle of a car.
This could be a solid axle or a fixed differential and half shafts to the wheels. The trailing arms
are kept fairly long so as to keep the vertical movement of the wheels as straight as possible,
without creating toe-in and toe-out. (This is not a problem with a solid rear axle.)
With hard mounted differential and half shafts trailing arm suspension is often made up of both
an upper link arm and the primary lower link arm. This helps to avoid the issue with toe
changes. At the same time, it keeps the wheels vertical during the travel of the suspension to
avoid camber changes.
All in all, this tends to be a somewhat older approach to performance suspensions, often now
used on trucks and 4X4 vehicles because they can be strong and avoid
Signs and symptoms of a damaged trailing arm
Trailing arms themselves are fairly resilient and don’t often wear out. However, the bushings can
wear out or get damaged over time. If these are not replaced it can result in damage to the
actual trailing arms.
• Clunking noises from the rear axle – You never want to hear clunking noises coming
from your vehicle. If you’re noticing them from the back of the vehicle when you drive
over bumps, accelerate, brake, turn, or put the vehicle into reverse, your trailing arm
could be the issue. The worst the problem gets, the louder the clunk will be. Take your
vehicle in to get inspected the moment you notice something sounds good to prevent
further damage.
• Your vehicle won’t stay in a straight line – Worn bushings or a broken trailing arm can
cause the rear axle to move independently from the chassis. This causes vehicles to
sway, as the rear wheels may actually change the direction of the vehicle.
• Your rear tires are wearing unevenly and excessively – While it’s true tires naturally
wear slightly unevenly (this is why tire rotations are important), if you notice significant
or accelerated wear, you should have your vehicle looked at. A broken trailing arm or
, worn bushing can send your suspension system into misalignment, which alters where
the vehicle’s weight sits. Ultimately this leads to premature tire wear.
• Your vehicle is shorter on one side – Your vehicle sits relatively level. If you notice that
one side is even an inch or so higher than the other, it’s a good indication that there’s an
issue with the suspension system. In the case of a trailing arm issue, worn bushings can
allow the rear springs to lift, thus altering the height of the vehicle.
•
Trailing arm designs for live axle setups often use only two or three links and panhard
rods to position the wheels laterally. The trailing arm design can also be used for
independent suspension configurations. Each wheel hub is positioned only by a large,
roughly triangular arm that rotates at one point in front of the wheel. This arm is almost
parallel to the ground when viewed from the side, but the angle changes according to the
unevenness of the road surface. Twist beam rear suspension is very similar except that the
arms are connected by beams, which are used to position the wheels and twist to provide
an anti-roll effect. Some aircraft use trailing arms in the landing gear and have oleo struts
for shock absorption. The trailing arm landing gear provides a smoother landing and a
more comfortable ride when taxiing compared to other types of landing gear.
ADVERTISE
Semi-trailing arm =
A semi-trailing arm suspension is a supple independent rear suspension system for automobiles,
where each wheel hub is positioned only by a large, almost triangular arm that pivots at two
points. Viewed from above, the line formed by the two pivots is somewhere between parallel
and perpendicular to the longitudinal axis of the car. usually parallel to the ground. Trailing arms
and multi-link suspension designs are often used on the rear wheels of vehicles to allow for a
flatter floor and more luggage compartment. Many small front-wheel drive vehicles have
MacPherson strut front suspension and trailing arm rear axles.
Many suspension systems have one or more such arms. If the primary structural attachment is a
trailing arm, then it is typically called a trailing arm suspension. The typical setup is an arm
attached to the chassis with a pivot that has it’s axis Across the chassis side to side.
The trailing arm is the piece of the suspension system that connects the vehicle’s axle to its
chassis. In addition to the trailing arm itself are the trailing arm bushings. These are rubber or
polyurethane components that act as cushions and reduce friction between the suspension
parts.
The purpose of a trailing arm is to locate and control the movement of the rear axle of a car.
This could be a solid axle or a fixed differential and half shafts to the wheels. The trailing arms
are kept fairly long so as to keep the vertical movement of the wheels as straight as possible,
without creating toe-in and toe-out. (This is not a problem with a solid rear axle.)
With hard mounted differential and half shafts trailing arm suspension is often made up of both
an upper link arm and the primary lower link arm. This helps to avoid the issue with toe
changes. At the same time, it keeps the wheels vertical during the travel of the suspension to
avoid camber changes.
All in all, this tends to be a somewhat older approach to performance suspensions, often now
used on trucks and 4X4 vehicles because they can be strong and avoid
Signs and symptoms of a damaged trailing arm
Trailing arms themselves are fairly resilient and don’t often wear out. However, the bushings can
wear out or get damaged over time. If these are not replaced it can result in damage to the
actual trailing arms.
• Clunking noises from the rear axle – You never want to hear clunking noises coming
from your vehicle. If you’re noticing them from the back of the vehicle when you drive
over bumps, accelerate, brake, turn, or put the vehicle into reverse, your trailing arm
could be the issue. The worst the problem gets, the louder the clunk will be. Take your
vehicle in to get inspected the moment you notice something sounds good to prevent
further damage.
• Your vehicle won’t stay in a straight line – Worn bushings or a broken trailing arm can
cause the rear axle to move independently from the chassis. This causes vehicles to
sway, as the rear wheels may actually change the direction of the vehicle.
• Your rear tires are wearing unevenly and excessively – While it’s true tires naturally
wear slightly unevenly (this is why tire rotations are important), if you notice significant
or accelerated wear, you should have your vehicle looked at. A broken trailing arm or
, worn bushing can send your suspension system into misalignment, which alters where
the vehicle’s weight sits. Ultimately this leads to premature tire wear.
• Your vehicle is shorter on one side – Your vehicle sits relatively level. If you notice that
one side is even an inch or so higher than the other, it’s a good indication that there’s an
issue with the suspension system. In the case of a trailing arm issue, worn bushings can
allow the rear springs to lift, thus altering the height of the vehicle.
•
Trailing arm designs for live axle setups often use only two or three links and panhard
rods to position the wheels laterally. The trailing arm design can also be used for
independent suspension configurations. Each wheel hub is positioned only by a large,
roughly triangular arm that rotates at one point in front of the wheel. This arm is almost
parallel to the ground when viewed from the side, but the angle changes according to the
unevenness of the road surface. Twist beam rear suspension is very similar except that the
arms are connected by beams, which are used to position the wheels and twist to provide
an anti-roll effect. Some aircraft use trailing arms in the landing gear and have oleo struts
for shock absorption. The trailing arm landing gear provides a smoother landing and a
more comfortable ride when taxiing compared to other types of landing gear.
ADVERTISE
Semi-trailing arm =
A semi-trailing arm suspension is a supple independent rear suspension system for automobiles,
where each wheel hub is positioned only by a large, almost triangular arm that pivots at two
points. Viewed from above, the line formed by the two pivots is somewhere between parallel
and perpendicular to the longitudinal axis of the car. usually parallel to the ground. Trailing arms
and multi-link suspension designs are often used on the rear wheels of vehicles to allow for a
flatter floor and more luggage compartment. Many small front-wheel drive vehicles have
MacPherson strut front suspension and trailing arm rear axles.
