TROUBLESHOOTING THE HMMWV - OD1616 - LESSON 1/TASK 1
The parallelogram steering linkage is a very popular steering system
for independent front suspension and is used on many of today's
The parallelogram steering system uses a
centerlink, otherwise known as an intermediate rod or track rod, to
connect the steering arms together.
The turning action of the
steering box is transmitted to the centerlink through the pitman arm.
The pitman arm also provides support for the centerlink.
components are connected by a hinge or ball joint. The pitman arm is
the component that transfers steering torque from the power steering
gear to the centerlink.
(b) Idler Arm. The centerlink is hinged on the opposite end of
the pitman arm by means of an idler arm. The idler arm supports the
free end of the centerlink and allows it to move left and right with
(c) Tie Rod.
The tie rod connects the steering arms together
and may be located in front of or behind the centerline of the wheel.
The tie rod is usually of a solid rod construction, but tubular
designs are also used.
(d) Tie Rod Ends.
Tie rod ends are used to form a flexible
link between the tie rod and steering arm. The tie rod end usually
is fastened to the knuckle arm with a tapered stud.
A socket is
provided within the tie rod end to hold the end of the stud, which is
in the form of a ball or yoke.
The socket also allows movement
between the knuckle arm and tie rod.
A lubrication fitting usually
is provided to keep the ball and socket joint properly lubricated. A
dust seal covers the tie rod end to prevent dust from entering the
joint and to prevent the loss of lubricant.
In the solid axle
configuration, the tie rod end is screwed onto the tie rod and is
secured with clamps.
(e) Adjusting Sleeves.
The inner and outer tie rods are
connected by adjusting sleeves.
These are tubular in design and
threaded over the inner and outer tie rods.
The adjusting sleeves
provide a location for toe adjustment.
Clamps and clamp bolts are
used to secure the sleeves. Some manufacturers require the clamps to
be placed in a certain position in relation to the tie rod top or