Professional_Tool_And_Equipment_News_May_2019 - 47

Service Bulletins (TSBs) related to our
issue. We found numerous TSBs on this
vehicle for a multitude of problems related
to components being added to the vehicle,
including aftermarket components added
to the diagnostic link connector (DLC).
We checked for any customer modifications and found none.
There was an additional TSB that met
some of the conditions we experienced,
but not all of them. In cases like this, we
have found it worthwhile to check the
TSB closer to verify the repair that is
listed will not apply to our vehicle. In this
case, the repair was to replace a steering column shaft seal that was interfering and causing a rub when the steering
column was rotated. We tested the seal
for clearance and detected no rubbing, so
we felt the TSB was not relevant.
Since we found no TSBs that pertained to this vehicle's issue, we looked
up the manufacturer specifications and
procedures for alignment and steering
angle reset, along with the recommended
tire size and pressure.
Part of your alignment process should
include checking to see if the proper size
tire is on the vehicle, especially with ECS
and ABS systems because these systems
are calibrated to the "roll out" or total
circumference of the tire. We have seen
many issues arise on trucks after the
owner has replaced the original tires and
wheels with "off-road" tires. We checked
the recommended tire size and air pressures which were correct.

INSPECT THE VEHICLE

Usually the inspection process
is part of the diagnosing process, but in the case of most undercar
issues it comes after scanning and gathering information. We placed the vehicle
on our alignment rack and noticed there
was some additional effort required to
turn the wheels, even while on the
turn plates.
Our first step was to check all of the
steering linkage to make sure there were
no components binding. All of the linkage appeared to be in good shape with
no apparent rust buildup. We then tested
the ball joints with a dial indicator and

p This TSB found in Mitchell 1 ProDemand indicated a possible issue
with a steering column seal.

p The Mitchell 1 ProDemand Tire Fitment Guide is a sure fire way to make sure the
correct tire size and pressures are installed on the vehicle.

other components for excessive play and
found none.
Our next step was to disconnect the
tie rods from each steering knuckle to
determine if the tightness was on one
side of the vehicle, or if it was an issue in
the steering gear box, steering column,
or steering linkage. Make sure you use
the correct tool to separate any steering
knuckle or tie rod end to avoid damaging components. We like the OTC 6295
set as it comes complete with all of the
tools to fit most cars and light trucks.
The left wheel turned from side to side
easily, but the right side took considerable effort to turn. We then removed the
steering knuckle from the ball joints and
found the lower ball joint was extremely
difficult to rotate.

THE REPAIR

On this model of vehicle, GM
used either a cast steel or an
aluminum control arm. The cast control arms had replaceable ball joints, and
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MAY 2019

the aluminum ones require replacing the
complete control arm rather than the ball
joint. Our vehicle had aluminum control
arms, so it was necessary to replace the
complete unit.
This brings us to a decision point: Is it
necessary to replace the upper and lower
control arms? Is it necessary to replace
both the left and right sides? You could
make an argument for either just replacing what is necessary to fix the immediate issue, or to replace everything due
to all the parts being the same age. You
could also go one step further in diagnosing the problem by comparing the ease
of movement between new components
and the ones on the vehicle.
Whichever choice you make, it is
vitally important to advise your customer
of your findings and provide them with
enough information, along with your
suggestion based on the findings and
your experience, for them to make the
best decision that fits their circumstance.
Remember, safety is an extremely
PROFESSIONAL TOOL & EQUIPMENT NEWS

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