Troubleshooting Guide - Clutch Concerns

TO ISOLATE CLUTCH CONCERNS FROM TRANSMISSION CONCERNS, OPERATE THE TRANSMISSION AT NO-LOAD. ON 4X4 MODELS, PLACE THE TRANSFER CASE IN NEUTRAL. REMOVE THE DRIVESHAFT ON 4X2 MODELS. RUN ENGINE AT 3000 RPM AND OPERATE TRANSMISSION THROUGHOUT RANGES WITH THE CLUTCH ENGAGED. IF HARD SHIFTING CONCERN (POWER TO TRANSMISSION) DISAPPEARS, THE CONCERN MAY BE IN THE CLUTCH SYSTEM.

AN IMPROPERLY OPERATING CLUTCH CAN RESULT IN HARD SHIFTING THAT IS MOST NOTICEABLE IN 1st, 2nd AND REVERSE. IT IS IMPORTANT THAT THE HYDRAULIC RELEASE MECHANISM IS WORKING PROPERLY. CONTINUED OPERATION WITH A DEFECTIVE CLUTCH SYSTEM MAY RESULT IN PREMATURE SYNCHRONIZER WEAR OR DAMAGE.
Hard shifting or difficulty engaging the transmission gears may be the result of improper clutch function. Check the release system travel. Minimum travel for the concentric slave cylinder bearing (4.9L, 5.0L and 5.8L engines) and the external system slave cylinder push rod (7.3L diesel and 7.5L engines) is 11 mm. If system travel is less than 11 mm, refer to TSB 88-18-10 for release system concern diagnosis. Possible concerns include excessive flexing of the dash panel or cracked dash panel reinforcement at the clutch master cylinder mounting and air/water in the hydraulic line.

If the release system travel is greater than 11 mm, and the clutch is suspected, check for clutch reserve as follows:

1. Set the parking brake and put the transmission in neutral.

2. With the clutch pedal fully depressed, shift into reverse, then shift half way between reverse and neutral to defeat the transmission synchronizer.

3. Allow the clutch pedal to fully return and adjust the shift lever position to obtain light contact between the transmission gear teeth. A slight grind will occur.
4. Slowly depress the clutch pedal until gear contact grinding stops. Measure the clutch pedal travel from this pedal position to the full down position.

This clutch reserve dimension should be at least 1 1/2". If the reserve is less than 1-1/2", and there are no hydraulic control system concerns, remove the transmission and check for excessive clutch wear. On the 7.3L diesel and 7.5L engines, check for release bearing contamination and binding on the bearing retainer. Replace the clutch and/or release bearing as required.
OTHER APPLICABLE ARTICLES: 88-18-10, 90-5-9
SUPERSEDES: 88-26-13
WARRANTY STATUS: INFORMATION ONLY
OASIS CODES: 5100, 5104, 5200, 5300, 5500, 5550, 7100, 7113