GRINDING OR TICKING NOISE WITH CLUTCH PEDAL FULLY DEPRESSED

SUBJECT: GRINDING OR TICKING NOISE WITH CLUTCH PEDAL FULLY DEPRESSED (INSTALL NEW PUSH ROD)

MODELS: 1992-93 C/K TRUCKS EQUIPPED WITH 4.3L (RPO LB4) OR 5.OL (RPO L03) AND 5-SPEED MANUAL TRANSMISSION

CONDITION

Some owners of 1992-93 C/K trucks equipped with 4.3L or 5.OL engines and 5-speed manual transmission may comment that their vehicle experiences a grinding or ticking noise with the clutch pedal fully depressed. The customer may also comment that when the vehicle is stopped, the transmission is difficult to engage into lst gear or grinds when engaging reverse. This noise normally quits when the clutch pedal is slightly released from the fully depressed position.

CAUSE

Over-travel of the clutch system causing the pressure plate diaphragm spring to contact the clutch hub.

CORRECTION

Replace the clutch push rod (P/N 15974712). This push rod is 4.5mm shorter than the existing push rod and is gold in color. The existing, longer push rod is silver. Any longer, silver push rods in dealer stock can be used satisfactorily in 5.7L, 6.2L, 6.5L, or 7.4L applications.

This new shorter rod was used on trucks starting with the following VIN breakpoints:

Fort Wayne (Z) GMC PZ522363 Pontiac East (E) GMC PE548816 Oshawa (1) GMC P1539180

SERVICE PROCEDURE (FIGURE 1)

1. Set parking brake.

2. Remove clutch master cylinder retaining nuts.

3. Remove clutch master cylinder from front of dash and move aside.

4. Pry clutch push rod retainer from stud on side of clutch pedal.

5. Remove clutch push rod from vehicle through front of dash.

6. Install new, shorter clutch push rod by reversing above procedure.

7. Torque clutch master cylinder mounting nuts to 15 N-m (11 lbs. ft).

SERVICE PARTS INFORMATION

P/N Description Qty --- ----------- --- 15974712 Rod Assembly 1

Parts are expected to be available from GMSPO on 5/10/93.

WARRANTY INFORMATION

For vehicles repaired under warranty, use:

Labor Description Labor Time Op ----------- ---------- ----- K0080 Push Rod and/or Seal, See Applicable Clutch Pedal - Replace Labor Time Guide

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.