Clutch Assembly - Diagnosis And Testing

Road test and inspect components to determine a clutch problem. Road test the vehicle at normal speeds. Shift the transmission through all gear ranges and observe clutch action. If clutch chatters, grabs, slips or does not release properly, remove and inspect clutch components. If problem is noise or hard shifting, further diagnosis may be needed to the transmission and driveline component.

CLUTCH CONTAMINATION

Contamination is a frequent cause of clutch malfunctions. Oil, water or clutch fluid on the clutch disc and pressure plate surfaces will cause chatter, slip and grab. Oil contamination indicates a leak at either the rear main seal or transmission input shaft. Clutch fluid leaks are usually from damaged slave cylinder push rod seals. Heat buildup caused by slippage between the pressure plate, disc and flywheel can bake the oil residue onto the components. The glaze-like residue ranges in color from amber to black.

Road splash contamination is dirt/water entering the clutch housing due to loose bolts, housing cracks. Driving through deep water puddles can force water/road splash into the housing through such openings.

IMPROPER RELEASE OR CLUTCH ENGAGEMENT

Clutch release or engagement problems can be caused by worn or damaged clutch components.

Release problems can cause hard shifting and noise. Look for leaks at clutch cylinders, connecting line and loose slave cylinder bolts. Also worn/loose release fork, pivot stud, clutch disc, pressure plate or release bearing.

Engagement problems can cause slip, chatter/shudder and noisy operation. The causes may be clutch disc contamination, wear, distortion or flywheel damage.

CLUTCH MISALIGNMENT

Clutch components must be in proper alignment with the crankshaft and transmission input shaft. Misalignment caused by excessive runout or warpage of any clutch component will cause grab, chatter and improper clutch release.

CLUTCH COVER AND DISC RUNOUT

Check the clutch disc before installation. Axial (face) runout of a NEW  disc should not exceed 0.50 mm (0.020 in.). Measure the runout about 6 mm (1/4 in.) from the outer edge of the disc facing. Obtain another disc if the runout is excessive.

Visually check the condition of the clutch before installation. Be careful when handling the cover and disc. Impact can distort the cover, diaphragm spring, release fingers and the hub of the clutch disc. If the clutch or disc appears to be damaged, do not install it, obtain a new clutch and disk set.

A frequent cause of clutch cover distortion is improper bolt tightening. Use a star pattern and follow the proper procedure. Refer to DISC, CLUTCH, REMOVAL AND INSTALLATION .

FLYWHEEL RUNOUT

Check flywheel runout whenever misalignment is suspected. Measure runout at the outer edge of the flywheel's friction surface with a dial indicator.

Common causes of runout are:

• heat warpage
• improper machining
• incorrect bolt tightening
• improper seating on crankshaft flange shoulder
• foreign material on crankshaft flange

Minor flywheel scoring is acceptable. Replace the flywheel if scoring is severe or the flywheel is damaged.

Clean the drive plate surface before mounting the flywheel. Dirt and grease on the drive plate surface may cock the flywheel causing excessive runout. Use new bolts when remounting a flywheel and secure the bolts with Mopar™ Lock And Seal or equivalent. Refer to FLYWHEEL, REMOVAL AND INSTALLATION .

DIAGNOSIS CHART

CONDITION	POSSIBLE CAUSES	CORRECTION
Disc facing worn out.	1. Normal wear.	2. Replace clutch assembly and the dual mass flywheel. Verify the bearing contact surface with the diaphragm spring, if there are marks of overheating or excessive wear replace the bearing.
	2. Driver frequently rides (slips) the clutch. Results in rapid overheating and wear.	2. Replace clutch assembly and the dual mass flywheel. Verify the bearing contact surface with the diaphragm spring, if there are marks of overheating or excessive wear replace the bearing.
	3. Insufficient clutch torque capacity.	2. Replace clutch assembly and the dual mass flywheel. Verify the bearing contact surface with the diaphragm spring, if there are marks of overheating or excessive wear replace the bearing.
Clutch disc facing contaminated with oil, grease, or clutch fluid.	1. Leak at rear main engine seal or transmission input shaft seal.	1. Replace appropriate seal. Replace clutch assembly if they have been contaminated. Inspect the dual mass flywheel and replace if contaminated.
	3. Slave Cylinder leaking.	3. Replace the slave cylinder and inspect hydraulic clutch lines. Replace clutch assembly if they have been contaminated.
Clutch is running partially disengaged, or slips while driving.	1. Release bearing sticking or binding and does not return to the normal running position.	1. Verify failure. Replace the release bearing as necessary.
	2. Release lever installed incorrectly.	2. Check for proper installation of release lever.
Facing on flywheel side of disc torn, gouged or worn.	1. Flywheel surface scored or nicked.	1. Correct surface condition if possible. Replace flywheel and clutch assembly as necessary.
	2. Clutch disc sticking or binding on transmission input shaft.	2. Inspect components and correct/replace as necessary.
Clutch disc facing burnt. Flywheel and cover pressure plate surfaces heavily glazed.	1. Frequent operation under high loads or hard acceleration conditions.	1. Replace flywheel and clutch assembly. Check release bearing for heat damage or scoring and replace if necessary. Alert driver to problem cause.
	2. Driver frequently rides (slips) clutch. Results in rapid wear and overheating of disc and cover.	1. Replace flywheel and clutch assembly. Check release bearing for heat damage or scoring and replace if necessary. Alert driver to problem cause.
Clutch discs binds on input shaft splines.	1. Clutch disc hub splines damaged during installation.	1. Replace clutch assembly.
	2. Input shaft splines rough, damaged, or corroded.	2. Clean and lubricate shaft splines if possible. Replace input shaft if necessary.
Clutch discs rusted to flywheel or pressure plate.	1. Clutch not used for an extended period of time (e.g. long term vehicle storage).	1. Replace clutch assembly and flywheel if necessary.
Clutch will not disengage properly.	1. Low hydraulic linkage fluid level.	1. Add hydraulic linkage fluid.
	2. Clutch cover loose.	2. Follow proper bolt tightening procedure.
	3. Clutch discs bent or distorted.	3. Replace clutch assembly. Inspect the dual mass flywheel and bearing, inspect and replace as necessary.
	4. Clutch cover diaphragm spring bent or warped.	3. Replace clutch assembly. Inspect the dual mass flywheel and bearing, inspect and replace as necessary.
	5. Release fork bent or fork pivot loose or damaged.	5. Replace fork or pivot as necessary. Inspect the bearing and diaphragm spring, if necessary replace the clutch assembly and bearing as well.
	6. Clutch master or slave cylinder failure.	6. Replace hydraulic linkage assembly and inspect clutch disc for contamination. Replace clutch assembly if contaminated by fluid.
	7. Incorrect slave cylinder installed.	7. Install correct slave cylinder.
Clutch pedal squeak.	1. Pivot pin loose.	1. Tighten pivot pin if possible. Replace clutch pedal if necessary.
	2. Master cylinder bushing not lubricated.	2. Lubricate master cylinder bushing.
	3. Pedal bushings worn out or cracked.	3. Replace and lubricate bushings.
	4. Rough surface on front bearing retainer.	4. Replace front bearing retainer.
	5. Release bearing sleeve not lubricated at fork interface.	5. Apply grease to release bearing and fork interface.
	6. Release fork pockets not lubricated.	6. Apply grease to release fork pockets.
Clutch master or slave cylinder plunger dragging or binding	1. Master or slave cylinder components worn or corroded.	1. Replace clutch hydraulic linkage assembly.
Release bearing is noisy.	1. Release bearing defective or damaged.	1. Replace release bearing.
Contact surface of release bearing damaged.	1. Release bearing defective or damaged.	1. Replace the release bearing.
	2. Release bearing misaligned.	2. Check front bearing sleeve for damage/alignment. Repair as necessary.
	3. Wear or discoloration at the bearing to clutch interference is acceptable.	3. Re-install bearing and continue usage.