IGNITION DISTRIBUTOR ASSY. USE (UPDATED INFORMATION)

SUBJECT: IGNITION DISTRIBUTOR ASSEMBLY USAGE (INFORMATION UPDATE)

VEHICLES AFFECTED: 1992 MEDIUM DUTY TRUCKS WITH 6.0/7.0L GAS ENGINE

There have been several changes to the production distrubutor assembly in 1992 medium duty trucks with 6.0/7.0L gas engines (VIN codes P/M, RPO Codes LS0/LR0). Consequently, there are two different color ignition distributor caps.

All 1992 models with 6.0/7.0L gas engines built from start of production to March 3, 1992, were built with WHITE distributor caps (P/N 10474757). The white cap had all-aluminum terminals for reduced corrosion.

An additional product improvement went into production at the Tonawanda Engine Plant on March 3, 1992, when a new distributor assembly was installed on all 1992 6.0L and 7.0L engines (Engine Serial #T0303 --- and greater) This new assembly included coated components for enhanced corrosion protection. Now, it also has a BLACK distributor cap (P/N 10475118) with the same updated all-aluminum terminals. This was strictly a color change to the cap to return it to its original color.

The new corrosion resistant coating has been included on the mainshaft assembly pick-up coil, pole piece, and pick-up coil retainer. The rotor also has a new stainless rotor spring contact for improved durability.

NOTE: It is possible to determine the vintage of a black the distributor cap assembly by:

A. Checking the engine serial number located on the engine block just in front of the right cylinder head. If the number is greater than T0303---, the latest distributor is installed, or;

B. Pull one plug wire on the cap and check for vent hole (see Figure #1). The latest distributor will not have vents.

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.