SERVICE MANUAL UPDATE-SEC. 3F IGNITION LOCK CYLINDER REPL.

SUBJECT: SERVICE MANUAL UPDATE - SECTION 3F - IGNITION LOCK CYLINDER REPLACEMENT

VEHICLES AFFECTED: 1991-93 "J" (CHEVROLET) AND 1992-93 "N" MODELS

APPLICATION:

----------- 1991-93 "J" Series (Chevrolet Only)

1992-93 "N" Series

When drilling out the ignition lock cylinder housing assembly shear bolts, care must be taken to remove the steering column from the car. Both the wiper switch and the turn signal switch must be removed before drilling the bolts out.

There is a concern that metal shavings from the drilling of ignition lock cylinder shear bolts may enter the switches and Gause the switch to become inoperative.

The revised procedure below should be used.

REMOVE

1. Steering wheel and covers (see Section 3F).

2. Steering column from vehicle (see Section 3F).

3. Turn signal switch from steering column (see Section 3F).

4. Wash/wipe switch from steering column (see Section 3F).

IMPORTANT: Both the turn signal switch and wash/wipe switch have to be removed to prevent any metal shavings from entering the electrical components.

5. Lock cylinder housing assembly as follows:

o Put key in run position.

o Drill off heads of two shear bolts using a 6.5 mm (1/4") drill bit.

o Remove lock cylinder housing assembly.

o Remove threaded ends of shear bolts from lock cylinder housing assembly with locking type pliers.

o Clean all metal shavings from all parts after drilling.

INSTALL

1. Lock cylinder housing assembly with two shear bolts.

o Key in run position.

2. Tighten two shear bolts until bolt head separates from bolt body approximately 1 1.0 N.m (97 lbs. in.)

3. Wash/wipe switch onto steering column (see Section 3F).

4. Turn signal switch onto steering column (see Section 3F).

5. Steering column into vehicle (see Section 3F).

6. Steering wheel and covers (see Section 3F).

NOTE: Because the correct procedure must be followed when replacing ignition lock cylinders, Warranty will not be paid on turn signal or wiper/wash switches for 30 days after an ignition lock cylinder replacement.

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.