A/T - Vibration Or Drone Type Noise

TECHNICAL

Bulletin No.: 11-03-09-001A

Date: January 31, 2012

Subject: Vibration or Drone Type Noise

Models:
2011 Chevrolet Camaro
Equipped with V6 Engine and Automatic Transmission

Built After VIN Breakpoint B9145905

Supercede:
This bulletin is being revised to add information at the end of step 14 and a Note in the Warranty Information. Please discard Corporate Bulletin Number 11-03-09-001 (Section 03 - Suspension).

Condition

Some customers may comment on a vibration or drone type noise at 1150-1200 RPM or 61-72 km/h (38-45 mph) in 6th gear and TCC on.

This vibration or drone type noise is present at the above MPH range during light throttle application and will remain as long as the engine load remains constant during these conditions.

Correction

The front two rear suspension support (cradle) bushings will need to be replaced. Follow the procedure below to replace the bushings.

Note
To perform this procedure you will need the following Special Tools:
J-45725-A Bushing Replacer

CH-50559 Front Hub/Bearing Remover/Installer Kit

KM-500-2 Remover/Installer

1. Raise the vehicle. Support the vehicle with an adjustable jack under the rear differential. Refer to Lifting and Jacking the Vehicle in SI.

2. Remove both rear wheels. Refer to Tire and Wheel Removal and Installation in SI.

3. Remove the front portion of the exhaust. Leave the rear exhaust hangers connected for support. Use mechanics wire at the front portion of the exhaust that was removed to support the system. Refer to Exhaust Muffler with Resonator, Exhaust, and Tail Pipe Replacement in SI.

4. Remove the rear propeller shaft coupler to the rear drive flange. Be sure to put reference marks on the propeller shaft and drive flange to indicate the original position before removal.

Note
DO NOT reuse the propeller shaft bolts. Discard and replace with NEW only.

5. Mark the support (cradle) and body at all 4 corners indicating where the rear suspension support (cradle) meets the underbody of the vehicle. Place an adjustable jack under the rear differential.

Note
DO NOT reuse the bolts. Discard and replace with NEW only.

Note
Torque specification for bolts - 100 Nm (74 lb ft) and a final pass of 110 degrees.

6. Remove the front two bushing bolts of the rear suspension support (cradle).

Note
DO NOT reuse the bolts. Discard and replace with NEW only.

7. Loosen the rear bolts 12 complete rotations.

Note
The rear bolts must be replaced at the end of the repair. Use them during this procedure to aid in positioning of the support (cradle).

8. Remove the indicator tab located on the back of the bushing using an air chisel. This will allow the metal washer on the bottom part of the bushing to fit completely in the receiver.

9. Lower the adjustable jack to the point that the front support (cradle) is low enough to assemble the CH-50559 Front Hub/Bearing Remover/Installer Kit (1) and the KM-500-2 Remover/Installer Kit (2).

10. Be sure and clean all debris around the opening before installing the new bushing.

11. Install the new bushing using the J-45725-2A Bushing Replacer. Flip the bottom of the J-45725-4 Installer over so the flat portion of the installer rests on the flat part of the bushing.

Note
Make sure that the indicator tab on the new bushing points toward the rear of the vehicle when installing.

12. Repeat the previous steps for replacing the other side.

13. Tighten rear suspension support (cradle) bolts.

14. Inspect the rear alignment for correct rear toe adjustment.

Note
If there isn't significant improvement felt with vibration after bushing replacement, remove the bolts from the rear propeller shaft to the rear drive flange, turn the propeller shaft 120 degrees, reinstall the bolts and test drive. This procedure might have to be performed a second time.

Parts Information

Warranty Information

For vehicles repaired under warranty, use the table.

Disclaimer

TECHNICAL

Bulletin No.: 11-03-09-001

Date: December 08, 2011

Subject: Vibration or Drone Type Noise

Models:
2011 Chevrolet Camaro
Equipped with V6 Engine and Automatic Transmission

Built After VIN Breakpoint B9145905

Condition

Some customers may comment on a vibration or drone type noise at 1150-1200 RPM or 61-72 km/h (38-45 mph) in 6th gear and TCC on.

This vibration or drone type noise is present at the above MPH range during light throttle application and will remain as long as the engine load remains constant during these conditions.

Correction

The front two rear suspension support (cradle) bushings will need to be replaced. Follow the procedure below to replace the bushings.

Note
To perform this procedure you will need the following Special Tools:
J-45725-A Bushing Replacer

CH-50559 Front Hub/Bearing Remover/Installer Kit

KM-500-2 Remover/Installer

1. Raise the vehicle. Support the vehicle with an adjustable jack under the rear differential. Refer to Lifting and Jacking the Vehicle in SI.

2. Remove both rear wheels. Refer to Tire and Wheel Removal and Installation in SI.

3. Remove the front portion of the exhaust. Leave the rear exhaust hangers connected for support. Use mechanics wire at the front portion of the exhaust that was removed to support the system. Refer to Exhaust Muffler with Resonator, Exhaust, and Tail Pipe Replacement in SI.

8. Remove the indicator tab located on the back of the bushing using an air chisel. This will allow the metal washer on the bottom part of the bushing to fit completely in the receiver.

Warranty Information

For vehicles repaired under warranty, use the table.

Disclaimer