Technical Service Bulletins
|Publication Date: JULY 21, 1997|
|1997 F-150, F-250|
Some vehicles with the exhaust outlet in front of the rear wheel may experience a vibration and/or “booming” noise at off idle engine speeds between 650 and 1100 rpms at a very low vehicle speed. This may be caused by engine firing frequencies aligning with resonance frequencies of the exhaust system.
Install an exhaust damper onto the exhaust system to reduce the possibility of the resonance frequencies aligning and resulting in a boom and/or vibration. Refer to the following Service Procedure for details.
Verify the customer concern is related to the exhaust system vibration as follows. The engine should be fully warm before proceeding. Set the parking brake, start the engine and put the gear selector in “Drive.” With the brake pedal depressed, lightly tip in the throttle to raise engine speed through the 650-1100 rpm range. Allow the engine to come back to an idle. Several cycles may be necessary to duplicate the concern. If the concern is verified, continue with this TSB.
- Remove the existing U-clamp at the catalytic converter outlet. Refer to Figure 1.
Figure 1 – Article 97-15-24
- Install a new U-clamp (N804035-S100) in the same location as the one removed. Install the clamp with the legs facing down.
- Place the Exhaust Damper (F65Z-5G209-AA) on the legs of the clamp between the collar and the nuts and hand start the nuts onto the clamp. Refer to Figure 2.
Figure 2 – Article 97-15-24
- Orient the damper so that it is located outboard of the pipe and inside of the frame area. The beam or arm of the damper should be parallel to the ground and the damper facing up (refer to Figure 3).
Figure 3 – Article 97-15-24
- Make sure the damper is parallel to the ground and equally torque the nuts to 55 N-m (41 lb-ft) alternating between them.
|PART NUMBER||PART NAME|
OTHER APPLICABLE ARTICLES:
Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage
|971524A||Install Exhaust Damper||0.3 Hr.|
|BASIC PART NO.||CONDITION CODE|
403000, 702000, 702300, 703000, 703100, 703200, 703400