between the flywheel and the flange. If the flange is bent, the crankshaft must be replaced.
Other causes of clutch pedal pulsation include bent or maladjusted pressure plate release levers, warped pressure plate, or warped clutch disc. If either the clutch disc or pressure plate is warped, they must be replaced.
When adjustment or repair of the linkage fails to remedy problems with the clutch, the clutch must be removed for inspection. Any faulty parts should be discarded and replaced with new or rebuilt components. If replacement parts are not readily available, a decision to use the old components should be based on the manufacturer's recommendations and the maintenance supervisor.
Transmission or transaxle removal is required to service the clutch. Always follow the detailed directions in the service manual. To remove the clutch in a rear-wheel drive vehicle, remove the drive shaft, the clutch fork, the clutch release mechanism, and the transmission. With a front-wheel drive vehicle, the axle shafts (drive axles), the transaxle, and, in some cases, the engine must be removed for clutch repairs.
When the transmission or transaxle is removed, support the weight of the engine. Never let the engine, the transmission, or the transaxle be unsupported. The transmission input shaft, clutch fork, engine mounts, and other associated parts could be damaged.
After removal of the transmission or transaxle, remove the clutch housing from the rear of the engine. Support the housing as you remove the last bolt. Be careful not to drop the clutch housing as you pull it away from the dowel pins.
Using a hammer and a center punch, mark the pressure plate and flywheel. These marks are needed when reinstalling the same pressure plate to assure correct balancing of the clutch.
With the clutch removed, all components are to be cleaned and inspected for wear and damage. After cleaning, you should inspect the flywheel and pressure plate for signs of unusual wear, such as scoring or cracks. A straightedge should be used to check for war-page of the pressure plate. Using a dial indicator, measure the runout of the flywheel. The pressure plate release levers should show very limited or no signs of wear from contact with the release bearing. If excessive wear, cracks, or warpage is noted on the flywheel and/or pressure plate, the assembly should be replaced. This is also a good time to inspect the ring gear teeth on the flywheel. If they are worn or chipped, a new ring gear should be installed.
Be careful how you clean the parts of the clutch. Avoid using compressed air to blow clutch dust from the parts. A clutch disc con- tains asbestos - a cancer-causing substance.
While inspecting the flywheel, you should check the pilot bearing in the end of the crankshaft. A worn pilot bearing will allow the transmission input shaft and clutch disc to wobble up and down. Using a telescoping gauge and a micrometer, measure the amount of wear in the bushing. For wear measurements of the pilot bearing, refer to the service manual. If a roller bearing is used, rotate them. They should turn freely and show no signs of rough movement. If replacement of the pilot bearing is required, the use of a slide hammer puller will drive the bearing out of the crankshaft end. Before installing a new pilot bearing, check the fit by sliding it over the input shaft of the transmission. Then drive the new bearing into the end of the crankshaft.
Inspect the disc for wear; inspect the depth of the rivet holes, loose rivets, and worn or broken torsion springs. Check the splines in the clutch disc hub for a "like new" condition. The clutch shaft splines should be inspected by placing the disc on the clutch shaft and sliding it over the splines. The disk should move relatively free back and forth without any unusual tightness or binding. Normally, the clutch disc is replaced anytime the clutch is tom down for repairs.
Another area to inspect is the release bearing. The release bearing and sleeve is usually sealed and factory packed (lubricated). A bad release bearing will produce a grinding noise whenever the clutch pedal is pushed down. To check the action of the release bearing, insert your fingers into the bearing; then turn the bearing while pushing on it. Try to detect any roughness; it should rotate smoothly. Also, inspect the spring clip on the release bearing or fork. If bent, worn, or fatigued, the bearing or fork must be replaced.Continue Reading