Clutch - Judder

Classification:
MT93-002



Section:
Manual Transmission



Reference:
TECHNICAL BULLETIN NTB93-013



Models:
1989-92 Maxima, 1990-92 Stanza



Date:
January 19, 1993



MAXIMA/STANZA CLUTCH JUDDER


APPLIED MODELS:
1989-92 Maxima with Manual Transaxle
1990-92 Stanza with Manual Transaxle


SERVICE INFORMATION:

Some manual transmission Maxima or Stanza customers may experience a shaking sensation through the clutch pedal or throughout the whole vehicle when releasing the clutch when moving away from a stop. This condition, known as clutch judder, is due to vibration of the pressure plate caused by the tilting of the release bearing when compressing the clutch diaphragm spring. The tilt is caused by incorrect contact between the release bearing and the release lever. To correct this condition, a countermeasure release lever has been made available. In addition, reducing installed flywheel runout as much as possible will result in the lowest possible levels of clutch judder. The following parts must be used alone with the service procedure (if the vehicle is an 1989 or 1990 Maxima verify that a 9 bolt clutch cover is installed per NTB90-002):

Parts Necessary:





1. Flywheel with lowest possible installed runout; 0.15 mm (0.005 in.) maximum. Note: indexing the flywheel on the crankshaft flange can reduce the installed runout measured as shown in figure 1.

2. New clutch disc and clutch cover (Cover P/N 30210-85E01).

3. Countermeasure clutch release lever (P/N 30531-03E11).

SERVICE PROCEDURE:

Verify that the vehicle exhibits clutch judder when the vehicle is accelerating from a stop with an engagement speed of not less than 1000 rpm (if the engagement engine speed is less than 1000 rpm, the shaking or vibration is not due to clutch judder, but due to vibration of the engine; also known as "lugging" and is a normal condition).

Remove the transaxle assembly from the vehicle. Install a magnetic base dial indicator to the rear of the engine block to measure the variation in clutch cover finger height. If the variation if less than 0.5 mm (0.020 in.), replace the clutch release lever with the countermeasure part specified above. Inspect the release sleeve for wear. If there is detectable wear, the clutch housing must be replaced. Reassemble.



FLYWHEEL INSPECTION

If the variation in finger height is near 0.5 mm (0.020 in.), or higher, remove the clutch cover and inspect the flywheel for signs of heat damage and runout. If it is warped, heat checked or has measurable runout, it should be replaced. Remeasure the runout, and ensure that it is as low as possible. The lower the runout, the less clutch judder that will result.


INSTALLATION

Replace the clutch disc and cover ensuring that the clutch cover bolts are tightened in several steps, pulling down the clutch cover toward the clutch disc evenly. Tighten bolts in numerical order. Torque the clutch cover bolts to final torque of 34-44 N-m (25-33 ft.lb.).



Remeasure the clutch cover finger height variation as before. If the variation is not less than 0.5 mm (0.020 in.), loosen the clutch cover bolts and retighten until the variation is within specification. Note: it is very important that the clutch cover bolts are tightened progressively and evenly; otherwise the clutch cover will be pulled down unevenly and clutch judder will result.

Once the clutch cover is installed, replace the release lever with a countermeasure part.

Inspect the release sleeve for wear. If there is detectable wear, the clutch housing must be replaced. Be careful not to allow grease to contaminate the clutch facing.

After all parts are inspected and in good condition, the transaxle can be reinstalled, the linkage connected, and the vehicle road tested. There should be no sign of clutch judder if this procedure is followed properly.





PARTS INFORMATION






WARRANTY INFORMATION