How to replace the clutch on a Freightliner Cascadia, DT12 automatic transmission
All the versions have a self-adjusting mechanism, with no wear indication or reset functions, and use organic friction material in the disk. The self-adjusting mechanism is locked in place, when the pressure plate is removed for service, by a sensor pin which contacts the face of the flywheel. See Fig. 1.However, care should be taken to prevent the pressure plate from being dropped, or resting on the sensor pin when removed, which could cause the mechanism to over-adjust, rendering the pressure plate unusable. Due to the self-adjusting characteristics of the pressure plate, the clutch assembly must always be replaced as a unit.
There are two general types of clutch assembly available, single and double disk, with specific dampening characteristics available depending on powertrain configurations.
- Park the vehicle on a level surface, shut down the engine, and set the parking brake. Chock the tires.
- Remove the battery connection at the negative post, including the batteries for the auxiliary Heating, Ventilation and Air Conditioning (HVAC), if equipped.
- Remove the transmission.
- Remove two of the three bolts, from each bolt group, holding the pressure plate to the flywheel. Make sure the five bolts required to attach the Clutch Lift Adapter, are included in those removed.
5. Insert the clutch disk alignment tool DDE DSN012T20022 in the pilot bearing bore.
6. Loosen each remaining clutch bolt, in the four bolt groups, incrementally in a star pattern, until the pressure plate spring is unloaded. Do not remove the bolts.
7. Install the Clutch Lift Adapter (DDE DSN012T16001), on a shop supplied clutch jack, and secure it to the pressure plate with the retaining pins.
Notice: The pressure plate has an internal adjustment mechanism, which cannot be reset. The pressure plate does not need to be “caged,” and is designed not to adjust during removal, but rough handling or an improper resting position could affect the adjustment. Do not drop the pressure plate, and always store it resting on the friction surface to prevent unintended adjustment.
8. Remove the remaining bolts, and withdraw the clutch. If the pressure pate is removed from the jack, it should be stored with the weight resting on the friction surface.
Inspect the flywheel surface, starter ring, and pilot bearing. Repair as necessary.
