GM Service Manual Online
For 1990-2009 cars only
  1. Verify/duplicate the customer concern. If the customer concern can be duplicated, proceed to step 2.
  2. Perform the following input shaft spin down test.
  3. 2.1. Set the parking brake and place the vehicle in neutral.
    2.2. Start the engine and allow the vehicle to idle.
    2.3. Gently move the shifter toward the reverse gate and continue to move the shifter until a light grind/rattle can be heard.
    2.4. Once the grind/rattle noise is observed, depress the clutch pedal and note the time required for the grind/rattle noise to stop. Normal spin down time, time required until grinding noise stops, is approximately 3 seconds.
       • If the noise stops, input shaft stops spinning, within approximately 3 seconds, the clutch disc/pressure plate and clutch hydraulic system are not the cause of the hard to shift into gear or grind into gear concern. Proceed to step 3.
       • If the noise does not stop within 3, inspect the clutch pedal travel and clutch fork travel as described below.
     - Clutch Pedal Travel Measurement
     - Measure the clutch pedal travel refer to Clutch Hydraulic System Diagnosis . Pedal travel should be between 117-137 mm (4.6-5.4 in). If the clutch pedal travel is not between 117-137 mm (4.6-5.4 in), check for:
       • Carpet or floor mat under pedal.
       • Faulty bushing/damaged pedal.
     - Clutch Fork Travel Measurement
     - Measure the clutch fork travel refer to Clutch Hydraulic System Diagnosis . If the clutch fork travel is less than 10.80 mm (0.43 in) check for the following:

            Important: The first four bullets require master/slave cylinder replacement.

       • Fluid leak in hydraulic system
       • Damage to the front of the dash
       • Air in system
       • Damaged master/slave cylinder
       • Master/slave cylinder improperly installed
     - If pedal travel and fork travel are OK and clutch hydraulics are functioning properly, check for:
       • Bent fork
       • Damaged pressure plate and/or clutch disc
  4. Attempt to verify the hard to shift into the gear concern with the engine OFF.
  5. • If the concern is not observed with the engine OFF, check for:
       - Damaged blocker ring, blocker ring teeth rounded off.
       - Burnt blocker ring/blocker ring friction material debonded.
       - Oversized blocker ring, can check with feeler gage for clearance between the blocker and the gear.
       - Missing circular spring.
       - Worn or damaged shift fork pad/bushing
       - Synchronizer sleeve tooth points damaged.
    • If the concern is observed with the engine off, check for :
       - Shift cable retainer clip loose/missing
       - Damaged/kinked shift cable.
       - Damaged shift tower components.
       - Shifter assembly damaged/broken.