'CLICKING' NOISE WHEN STEERING WHEEL IS ROTATED

Subject: CLICKING NOISE WHEN STEERING WHEEL IS ROTATED

Model and Year: 1990 CORVETTE

TO: ALL CHEVROLET DEALERS

Condition:

---------- A "clicking" noise may be heard when the steering wheel is turned.

Cause:

------ The Supplemental Inflatable Restraint (SIR) coil lockspring, which holds the coil in a centered position during service, may be missing or broken. The brass colored lockspring may not be strong enough to withstand compression during assembly. The SIR system continues to function normally.

Three conditions may be found:

1. Black lockspring - latest design, not subject to breakage.

2. Brass colored lockspring - early design, subject to breakage.

3. No lockspring - Some steering columns may have been built without locksprings from VIN's #1 14400 to #1 15822 (Man. Trans.) and #1 16055 (Auto. Trans.).

Correction:

------------ If the "clicking" noise is heard, or if removal of the SIR coil assembly is required during steering column service, check for a broken lockspring as follows:

1 . Disconnect negative battery cable.

2. Disable SIR system following Service Manual instructions.

3. Place wheels in the straight ahead position before removing coil.

4. Refer to 1990 Corvette Service Manual for complete instructions on removing the coil assembly from the steering column. Before removing the coil assembly from the column, tape the coil assembly to hold it in the centered position, as shown in the illustration.

IMPORTANT: If the coil is left free to rotate, follow the centering procedures in Section 3F4A of the 1990 Corvette Service Manual.

5. Remove the coil from the column, turn the coil over, and inspect the lockspring for broken or missing pieces as shown in the illustration.

a. If the lockspring is black, it is not subject to breakage. Leave the lockspring in place.

b. If the spring is brass colored, and is not broken, leave it in place.

c. If the spring is brass colored, and is broken, remove all the pieces of the spring and discard. It is not necessary to replace the lockspring with a new one.

NOTICE: All pieces of the broken lockspring must be removed, or serious damage to the steering column may result.

d. if the spring is missing, it is not necessary to replace it.

6. Replace the coil assembly in the steering column.

7. Enable SIR system.

8. Reconnect the negative battery cable.

Warranty Information: Use labor operation No. C8800, 1.2 hrs.

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.