Hood/Grille - Wind Noise at Highway Speeds
NO: 23-25-97GROUP: Body
DATE: May 2, 1997
SUBJECT:
Windnoise (Whistle) Around Grille Area
THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 23-27-96, DATED APR. 19, 1996, WHICH SHOULD BE REMOVED FROM YOUR FILES AND NOTED IN THE 1996 TECHNICAL SERVICE BULLETIN MANUAL (PUBLICATION NO. 81-699-97010). 1997 VEHICLES HAVE BEEN ADDED TO THE MODEL LIST AND VEHICLES UTILIZING CAVITY 4 GRILLES ARE NOW INCLUDED. ALL REVISIONS ARE HIGHLIGHTED WITH **ASTERISKS**.
MODELS:
1996 - **1997** (BR) Ram Truck
SYMPTOM/CONDITION:
Vehicles may exhibit a condition where a windnoise whistle occurs from the front of the vehicle. This condition can occur while driving the vehicle at highway speeds between 45 - 65 mph or at slower speeds when driving into a headwind.
DIAGNOSIS:
Check the cavity number on the back side, center of the grille (Figure 1). If CAV3 or **CAV4** is stamped on the grille, continue on with the diagnosis. If CAV3 or CAV4 is not stamped on the grille, then the grille is not the likely source of the windnoise.
NOTE:
THIS REPAIR WILL NOT CORRECT THE ABOVE CONDITION IF CAV3 OR **CAV4** IS NOT STAMPED ON THE GRILLE.
Test drive the vehicle between 45-65 mph in non-turbulent conditions (not in another vehicles wake). Verify that the windnoise whistle occurs from the front of the vehicle.
Tape the hood-to-grille gap as shown in Figure 2.
Repeat test drive with the grille taped. If the problem still exists, the fault of the condition is not the grille and further diagnosis will be necessary. If the whistling has disappeared, then perform the following Repair Procedure.
PARTS REQUIRED:
5 Feet 04882735 30 foot roll Of 1/4 in. Thick x 3/8 in.
Wide Closed Cell PVC Foam Tape
REPAIR PROCEDURE:
This bulletin involves installing (1/4 in. thick x 3/8 in. wide) closed cell PVC foam (p/n 04882735) between the hood and grille gap.
1. Open the hood.
2. Remove the bolt holding the bottom of the grille to the grille bracket.
3. Remove the bolts holding the sides of the grille to the grille bracket.
4. Remove the six nuts holding the grille to the hood (Figure 3).
5. Separate grille from vehicle (do not remove the grille bracket assembly).
6. Cut off the plastic spacer tabs on the top of the grille as shown in Figure 4.
7. Clean the inside top edge of the grille with isopropyl alcohol to ensure proper adhesion of the closed cell PVC foam.
8. Apply approximately five feet of the closed cell PVC foam (p/n 04882735) on the inside top edge of the grille as shown on Figure 5 and 6. Be sure to line-up the edge of the foam strip to the inside edge of the grille.
9. Trim excess foam strip from grille.
10. Install the grille onto the grille bracket.
11. Install the nuts holding the grille to the hood. Tighten the nuts to 2.5 Nm (22 in. lbs.) of torque.
12. Install the bolts that hold the sides of the grille to the bracket. Tighten the bolts to 2.5 Nm (22 in. lbs.) of torque.
13. Install the bolt that hold the bottom of the grille to the bracket. Tighten the bolt to 2.5 Nm (22 in. lbs.) of torque.
14. Close the hood and retest to verify that the whistling noise has been eliminated.
POLICY: Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Labor Operation No: 23-02-01-91 0.9 Hrs.
FAILURE CODE: XX - Service Adjustment