moving the distributor cover. The waterproof
seal under the cover of a good distributor need
not be broken for testing the condition of the
Care should be taken when mounting
distributors which use a nylon drive
gear. To prevent damage to the gear
DISTRIBUTOR VISUAL INSPECTION.
when mounting the shaft into the
drive chuck, place a small piece of
The distributor should be inspected visually be-
rubber hose over each one of the
fore it is installed in the distributor tester. Ex-
three chuck jaws. It is then possible
amine and note the condition of the following:
to tighten the chuck without damaging
a. Distributor shaft side clearance and end
DISTRIBUTOR RESISTANCE TEST.
b. Distributor shaft bearings and bushings for
w e a r and smoothness of operation.
the distributor primary circuit from the primary
d. B r e a k e r plate bearings or bushing for
terminal, through the points, to the distributor
wear, smoothness of operation and lubri-
body. Excessive resistance in any portion of the
e. Cam wick for proper lubrication.
distributor primary circuit will prevent the coil
from performing at full efficiency.
f . Breaker cam for smoothness and lubri-
Procedure for checking distributor resistance:
h. Contact points for alignment, pitting and
a. With MOTOR SWITCH positioned for prop-
b u r n i n g ; and rubbing block wear.
er distributor rotation, turn Speed Control
i. Vacuum advance linkage for alignment,
for zero rpm (no rotation of distributor
wear and binding, -
b. Clip the distributor and ground test leads
of the tester together.
c. Set tach-dwell selector switch to CAL po-
Procedure for mounting the distributor.
sition and adjust calibrator until dwell
m e t e r pointer reads on the Set Line,
a. Using the elevation crank, raise clamp
arms high enough to permit shaft of dis-
d. Separate the test leads and connect the dis-
t r i b u t o r being mounted to clear drive
tributor lead (red) to the distributor pri-
mary terminal, and the ground lead (black)
b. Position distributor in clamp with vacuum
to the ground stud on the clamping arm.
chamber pointing to the right. Tighten
e. With distributor points closed, dwell meter
clamp arms securely on machined surface
pointer should read within black bar at
of distributor body. If vacuum advance ro-
right end of distributor resistance scale.
tates entire distributor install proper a-
dapter. (Four adapters are included in the
(1) If the dwell meter pointer reads in the
c. Using the elevation crank, lower the dis-
white area to the left of the black bar,
tributor until the drive gear or drive shaft
excessive resistance is present in the
enters the drive chuck. For other types
distributor primary circuit.
of distributor shafts select one of the four
(2) To locate the cause of the excessive
adapters supplied with the unit. Do not
bottom the distributor shaft in the drive
by-step through the distributor's elec-
t r i c a l circuit from the primary ter-
d. Tighten the chuck. For an
minal to the ground return. Where the
ternal adjustment type of distributor, cen-
resistance reading on the dwell meter
ter the drive gear between its upper and
changes considerably from one point to
lower limits of end play travel before tight-
a n o t h e r , correct the high resistance
ening the chuck, Do not try to raise or
lower the distributor after the drive chuck
has been tightened.