Service Manual

7.11
CLUTCHING (PVT)
7
DRIVE CLUTCH SERVICE
Spring Specifications
The drive clutch spring has two primary functions:
1. To control clutch engagement RPM. The springs,
which have a higher rate when the clutch is in
neutral, will increase clutch engagement RPM.
2. To control the rate at which the drive belt moves
upward in the drive clutch sheaves. This is referred
to as drive clutch upshift.
There are other components which control upshift, but the
spring is one of the primary components in insuring
optimum performance. It is very important that the spring
is of the correct design and is in good condition.
The drive clutch spring is one of the most critical components of the PVT
system. It is also one of the easiest to service. Due to the severe relaxation the
spring is subject to during operation, it should always be inspected for
tolerance limits during any clutch operation diagnosis or repair.
With the spring resting on a flat surface, measure its free length from the outer
coil surfaces as shown. Refer to the spring specification chart for specific free
length measurements and tolerances. Also check to see that spring coils are
parallel to one another. Distortion of the spring indicates stress fatigue,
requiring replacement.
CAUTION
Never shim a drive clutch spring to increase its
compression rate. This may result in complete
stacking of the coils and subsequent clutch
cover failure.
Primary Clutch Springs
PART
NUMBER
COLOR CODE
WIRE
DIAMETER
FREE LENGTH
± .125”
PART
NUMBER
COLOR CODE
WIRE
DIAMETER
FREE LENGTH
± .125”
7041021 Plain .157" 4.38" 7041168 Green .177" 3.05"
7041022 Black .140" 4.25" 7043349 Red / White .200" 2.58"
7041063 Purple .168" 4.37" 7043372 Red / Blue .187" 2.56"
7041132 White .177" 2.92" 7043382 Red / Green .177" 2.63"
7041157 Blue / Green .177" 2.53" 7043500 Red / Black .200" 2.82"
Red/White
7043349
Red/Blue
7043372
Red/Green
7043382
Red/Black
7043500