SERVICE MANUAL UPDATE SEC. 6A ENGINE MECHANICAL REVISED

SUBJECT: SERVICE MANUAL UPDATE - SECTION 6A ENGINE MECHANICAL - UNDERSIZED BEARING ART REPLACEMENT (This bulletin has been revised to change the number from 91-616-100 to 91-610-100)

VEHICLES AFFECTED: 1991 SPRINT/FIREFLY

Figure 1 in this bulletin replaces the chart in Figure 138 on page 6A1-42 of the 1991 Sprint/Firefly Service Manual (ST370-91).

Refer to the table in Figure 1 for determining correct undersized bearing clearance.

MEASURED JOURNAL DIAMETER

| | 44.744-44.750 mm| 44.738-44.744 mm | 44.732-44.738 mm (1.7616-1.7618")| (1.7614-1.7616") | (1.7612-1.7614-) --------------------------------------------------------- LETTERS A GREEN AND RED | BLACK AND RED | RED ONLY STAMPED | | ON MATING B BLACK AND RED | RED ONLY | YELLOW AND RED SURFACE | | OF C RED ONLY | YELLOW AND RED | BLUE AND RED CYLINDER | | BLOCK UNDERSIZE BEARING TO BE INSTALLED

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.