Clutch unit: APTC wet clutch
Caution
Bold reference numbers in this section identify parts shown in this exploded view diagram. These parts do not appear
in the figures near the text.
APTC clutch unit description
The APTC system is a clutch system with follow-up torque and slipper clutch design to eliminate rear wheel hop under
braking.
The system offers the following advantages:
- It eliminates the negative effects associated with heavy engine braking when down shifting thereby ensuring smooth
sliding into corners (anti hop feature);
- It reduces the effort required to compress the clutch springs and disengage the clutch. The pull effort required to
operate the clutch lever is reduced, while retaining good feel (follow-up torque).
In the APTC system, the two sections of the clutch drum are coupled by helical splines.
It is this special design that provides the follow-up torque and anti-hop features using the axial component of driving
torque (under acceleration) and braking torque (under braking), respectively.
What happens is the clutch plate pack is compressed further under acceleration as a result of the driving torque (note
that clutch spring pressure has been reduced in the new system), whereas during extreme deceleration braking
torque partly removes the pressure causing the clutch plates to slip.
Before operating on the internal clutch parts, check for proper operation. Then deal with the problem in a systematic
manner.
The following is a list of possible causes of clutch malfunctioning.
A clutch which does not disengage may be caused by:
- excessive play of the control lever;
- distorted clutch plates;
- incorrect spring tension;
- faulty clutch mechanism;
- excessive wear of the drum or clutch housing.
file:///C|/Documents%20and%20Settings/F4i/My...anual/wsm/usa/Mon695_MY07_N_6A9_00.67.1.html (2 of 12) [10/7/2008 8:45:55 PM]