Buick LeSabre 1965 Service Manual page 440

CHASSIS SUSPENSION
TROUBLE DIAGNOSIS 7 - 1 3
Elimination of the roughness indi-
cates that propeller shaft is out of
balance. Continued roughness with
engine running alone indicates an
out of balance condition of engine.
b. Tire and Wheel Runout
Excessive vibration or s h a k e
similar to out of balanced tires
can be caused by excessive tire
or wheel runout. This runout may
be both radial and l a t e r a l .
Radial runout usually has greater
affect on vibration or shake than
lateral runout.
A dial indicator may be used to
check runout on wheel and tire
assemblies at points shown on
Figure 7- 5. Tire runout should be
checked immediately after the car
has been driven, as tires take a
"set" after standing for a short
period. NOTE: It should be
stressed that the runout found is
a mere indication and not proof of
the source of trouble.
Procedure:
1. Make certain that the wheel
lug nuts are tightened adequately
and evenly.
2. If checking front wheels and
tires make certain that wheel
bearings are correctly adjusted.
3. Mount the dial indicator on a
firm base and check total indica-
tor runout at the points indicated
in Figure 7-7.
100" RADIAL
125" LATERAL
.050" LATERAL
045" RADIAL
Figure 7-7—Runout Limit Specifications
4. If runout exceeds specifica-
tions check for the source of the
trouble and correct as necessary.