There are 6 different clutch assemblies used on this vehicle, depending on the engine application and the transmission. In order to perform the proper diagnosis and the correct repairs, it is important to understand which clutch assembly is being used and how it operates. The following components make up the clutch system:

Clutch Brake : The clutch brake is a disc, with friction material, that is tabbed to the input shaft. It is squeezed between the release bearing and the transmission front cover during clutch disengagement, to stop the rotation of the input shaft. It is used with non-synchronized transmissions to allow shifting into a gear while the vehicle is not moving.

Clutch Cable : The clutch cable transfers the clutch pedal motion to the clutch lever. The cable has adjustable ends for positioning the release yoke or fork.

Clutch Cover: The clutch cover is part of the pressure plate cover assembly. It retains the springs and other levers that operate the pressure plate. The clutch cover is bolted to the flywheel.

Clutch Disc: The clutch disc is referred to as the driven member. It is a flat plate that may have damper springs. Depending on the clutch assembly, it may have either 4 or 6 paddles. The friction material located on the paddles is clamped between the flywheel and the pressure plate. The disc hub is splined on the input shaft and delivers the engine torque to the transmission. Different friction materials are used to give smooth and long lasting clutch operation. For increased engine torque applications, two discs are sometimes used.

Clutch Lever : The clutch lever connects the clutch cable to the clutch cross shaft.

Clutch Pedal: The clutch pedal is mounted in the cab on a bracket. It is operated by foot pressure, swivels on a shaft, and assisted to the upright position by a spring.

Clutch Pedal Free Travel: The clutch pedal free travel is the amount the pedal moves before the clutch release bearing moves.

Clutch Pressure Plate: The clutch pressure plate is referred to as the driving member. It has a steel disc, with a machined surface, that is forced against the clutch discs by the springs in the clutch cover.

Clutch Pressure Plate Cover Assembly : The clutch pressure plate cover assembly consists of the pressure plate, the cover, and the springs that apply the clamping force to the clutch discs.

Clutch Release Bearing: The clutch release bearing is attached to the clutch pressure plate. It moves the springs in the pressure plate to release the clamping load. The bearing may require routine lubrication or may be a sealed style.

Clutch Release Yoke: The clutch release yoke rotates with the cross shaft. It has fingers that move the clutch release bearing.

Cross Shaft: The cross shaft is a two piece shaft that goes through the clutch housing and is supported by bushings. The clutch release yoke fastens to the cross shaft.

Pull Type Clutch : With the pull type clutch, the release bearing is pulled away from the pressure plate cover assembly during clutch disengagement.

Push Type Clutch: With the push type clutch, the release bearing is pushed towards the pressure plate cover assembly during clutch disengagement.

The C model medium duty vehicle uses a clutch cable to operate the clutch system. Movement from the clutch pedal is transmitted to the clutch lever and linkage through the clutch cable. Different configurations of linkage rotate the release yoke, depending if the clutch assembly is a pull type or a push type.

Proper placement or adjustment of the release bearing is critical for correct pull type clutch operation. If the release bearing is too close to the pressure plate cover assembly, it may prevent clutch brake operation. If the release bearing is too far from the pressure plate cover assembly, it may prevent complete clutch disengagement. On the RPO MPJ, improper clutch pedal free travel may cause release bearing failure.

RPO MPJ

The clutch assembly manufactured by Valeo is used with the 8.1L engine. The clutch is a 330.2 mm (13 in) push type. A clutch fork, that pivots on a ball stud in the clutch housing, is used to move the release bearing. Adjusting the clutch linkage moves the clutch fork for the proper clutch free travel.

RPO MTD

The clutch assembly manufactured by Valeo can be used with any of the engine or transmission applications. The clutch is a 355.6 mm (14 in) with a single cerametallic disc. The clutch operation is a diaphragm spring pull type. The clutch may be used with a clutch brake. The clutch release bearing travel is adjusted by loosening the lock ring on the collar and turning the coupler.

RPO MPL

The clutch assembly manufactured by Eaton Fuller can be used with any of the engine or transmission applications. The clutch is a 355.6 mm (14 in) with a single ceramic disc. The clutch operation is pull type. It is self-adjusting and referred to as the Eaton Soloâ. Sliding cams in the pressure plate cover assembly, move the pressure plate as the clutch discs wear. The release bearing requires routine lubrication for proper operation. The clutch may be used with a clutch brake.

RPO MWM

The clutch assembly manufactured by Eaton Fuller can be used with any of the engine or transmission applications. The clutch is a 355.6 mm (14 in) with a single cerametalix disc. The clutch operation is a stamped angle spring pull type. The clutch may be used with a clutch brake. The clutch release bearing travel is adjusted by manually turning the pressure plate inside of the clutch cover. A Kwik-Adjustâ aids the clutch adjustment. The release bearing requires routine greasing.

RPO MZE

The clutch assembly manufactured by Eaton Fuller can be used with any of the engine or transmission applications. The clutch is a 355.6 mm (14 in) with 2 cerametalix disc. The clutch operation is a stamped angle spring pull type. The clutch may be used with a clutch brake. The clutch release bearing travel is adjusted by manually turning the pressure plate inside of the clutch cover. A Kwik-Adjustâ aids the clutch adjustment. The release bearing requires routine greasing.

RPO MPK

The clutch assembly manufactured by Eaton Fuller is used with any of the engine or transmission applications. The clutch is a 355.6 mm (14 in) with 2 ceramic discs. The clutch operation is pull type. It is self-adjusting and referred to as the Eaton Soloâ. Sliding cams in the pressure plate cover assembly move the pressure plate as the clutch discs wear. The clutch also can be a maintenance free version. The clutch may be used with a clutch brake.