Primary Drive/Clutch - Buell 2002 S3T Service Manual

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PRIMARY DRIVE/CLUTCH

GENERAL
The purpose of the clutch is to smoothly disengage and
engage the engine from the rear wheel for starting, stopping
and shifting gears.
See Figure 6-13. The clutch is a wet, multiple-disc clutch with
six steel plates (1), one spring plate (2) and eight fiber (fric-
tion) plates (3) stacked alternately in the clutch shell (4). The
order of plate assembly, from inboard to outboard, is as fol-
lows:
F - St - F - St - F - St - F - Sp - F - St - F - St - F - St - F
(F = Fiber plate, St = Steel plate, Sp = Spring plate)
The fiber plates (clutch driving plates) are keyed to the clutch
shell (4), which is driven by the engine through the primary
chain. The steel plates (clutch driven plates) and the centrally
located spring plate (also a clutch driven plate) are keyed to
the clutch hub (5), which drives the rear wheel through the
transmission and secondary drive belt.
When the clutch is engaged (clutch lever released), the dia-
phragm spring (7) applies strong inward force against the
pressure plate (6). The pressure plate then presses the clutch
plates (1, 2 and 3) together, allowing no slippage between the
plates and causing the plates to turn as a single unit. The
result is that the rotational force of the clutch shell (4) is fully
transmitted through the "locked" clutch plates to the clutch
hub (5). As long as the transmission is set in a forward gear,
power from the engine will be transmitted to the rear wheel.
When the clutch is disengaged (clutch lever pulled to left han-
dlebar grip), the pressure plate (6) is pulled outward (by
clutch cable action) against the diaphragm spring (7), thereby
compressing the diaphragm spring. With the pressure plate
retracted, strong inward force no longer squeezes the clutch
plates (1, 2 and 3) together. The fiber plates (3) are now free
to rotate at a different relative speed than that of the steel (1)
and spring (2) plates (i.e. – slippage between the clutch
plates occurs). The result is that the rotational force of the
clutch shell (4) is no longer fully transmitted through the
"unlocked" clutch plates to the clutch hub (5). The engine is
free to rotate at a different speed than the rear wheel.
SYMPTOM CAUSE (CHECK IN FOLLOWING ORDER)
Clutch slips. Incorrect clutch release adjustment.
Worn clutch plates.
Clutch drags. Incorrect clutch release adjustment.
Worn clutch release ramps or balls.
Warped clutch steel plates.
Blade worn or damaged clutch gear splines.
Overfilled primary.
6-10 2002 Buell S3T: Drive/Transmission
b0422x6x
Table 6-1. Clutch Troubleshooting
6249
1
5
3 2 1
7
Clutch
engaged
1. Steel Plate (6)
2. Spring Plate
3. Fiber Plate (8)
4. Clutch Shell
Figure 6-13. Clutch Plates and Hub/Shell Assembly
REMEDY
Check and adjust clutch release mechanism.
Check service wear limits. Replace plates.
Check and adjust clutch release mechanism.
Replace release ramps and/or balls.
Replace clutch steel plates.
Replace clutch gear or hub as required.
Drain lubricant to correct level.
6.5
2
3
4
5 4
6
Clutch
disengaged
5. Clutch Hub
6. Pressure Plate
7. Diaphragm Spring