SPICER CLUTCH PROCEDURE FOR MEASUREMENT OF FREE PLAY

IMPROPER ADJUSTMENT OF CLUTCH PEDAL FREE TRAVEL CAN REDUCE CLUTCH AND CLUTCH RELEASE BEARING DURABILITY. THE SPICER CLUTCH USED IN THE TOP KICK REQUIRED LOWER PEDAL EFFORT THAN OTHER DESIGNS. THIS LOW PEDAL EFFORT IS PARTICULARLY NOTICABLE IN THE FIRST INCH OR SO OF PEDAL TRAVEL AFTER THE RELEASE BEARING HAS CONTACTED THE RELEASE LEVERS ON THE CLUTCH ASSEMBLY. THIS LOW INITIAL PEDAL FORCE, COUPLED WITH THE FLEXIBILITY INHERENT IN THE LINKAGE, MAY PROVIDE A FALSE INDICATION OF CLUTCH PEDAL FREE PLAY. THE CLUTCH PEDAL FREE PLAY SHOULD BE MEASURED AND ADJUSTED AT THE TURNBUCKLE BETWEEN THE FRAME MOUNTED IDLER LEVER AND THE CLUTCH CROSSHAFT LEVER. THE REQUIRED CLEARANCE, ELEVEN MILLIMETERS (0.45 INCHES) IS SHOWN IN FIGURE NO. 1. FOR FURTHER INFORMATION, PLEASE CONSULT SECTION 7C IN THE APPROPRIATE MEDIUM DUTY TRUCK SERVICE MANUAL. IT IS IMPORTANT TO NOTE THAT,--UNLIKE SOME SPICER CLUTCHES USED IN THE PAST, THE CLUTCH ASSEMBLY USED IN THE TOP KICK IS NOT INTERNALLY ADJUSTABLE. ALL ADJUSTMENTS MUST BE MADE IN THE CLUTCH LINKAGE. IN ADDITION, THE SPICER CLUTCH USED IN THE TOP KICK HAS A LOWER PEDAL EFFORT THAN OTHER CLUTCHES USED IN SIMILAR APPLICATIONS. THIS IS DUE TO THE DESIGN CHARACTERISTICS OF THE CLUTCH PRESSURE PLATE. A LIGHT PEDAL EFFORT IS NOT NECESSARILY AN INDICATION OF A WEAK PRESSURE PLATE. CLUTCH SQUEAL IS FREQUENTLY CAUSED BY IMPROPER DRIVING TECHNIQUES. THE CLUTCH MUST BE LET OUT COMPLETELY BEFORE THE ACCELERATOR IS DEPRESSED. THIS PROCEDURE IS CONTRARY TO THAT USED ON A GASOLINE POWERED ENGINE WHERE THE ENGINE SPEED IS INCREASED BEFORE THE CLUTCH IS ENGAGED. IF THE ENGINE SPEED WILL NOT START THE VEHICLE IN MOTION, A LOWER GEAR SHOULD BE SELECTED. THERE ARE CERTAIN INSTANCES WHEN THE ENGINE SPEED MUST BE INCREASED BEFORE ENGAGING THE CLUTCH IN ORDER TO START THE VEHICLE IN MOTION BUT THIS SHOULD BE AVOIDED IF POSSIBLE.

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.