Fulltext TSBs

Technical Service Bulletins

TSB
98-1-15
  • FENDERS – RANDOM HAIRLINE CRACKS “STAR CRACKING” IN REAR SHEET MOLDING COMPOSITE (SMC) FENDERS – DUAL REAR WHEEL VEHICLES OPERATING IN SEVERE DUTY CONDITIONS
Publication Date: JANUARY 19, 1998

LIGHT TRUCK:
1987-1997 F-350

This TSB article is being republished in its entirety to include 1997 model year vehicles.

ISSUE:

Random hairline cracks, “star cracking,” may occur in the rear Sheet Molding Composite (SMC) fenders on vehicles operating in an environment of loose surface debris and/or sub-zero temperatures. This may be due to the tires occasionally propelling rocks/debris into the unprotected area of the underside of the fender, resulting in the paint cracking on the exterior surface.

ACTION:

Determine if the paint or the SMC fender is cracked. If cracks in the SMC are evident, the rear fender exterior surface should be serviced by referring to the Service Procedure that follows. If the SMC is not cracked, refinish the exterior paint as per the normal Service Manual procedure.

SERVICE PROCEDURE

SMC REPAIR

  1. Clean both surfaces of the fender inside and out with wax and grease remover.
  2. Using a die grinder or equivalent, “U” groove out the top surface of the crack at least 25mm (1″) to each side of the crack about 1/2 to 3/4ths of the SMC thickness.

    CAUTION:DO NOT PENETRATE COMPLETELY THROUGH THE SMC.

  3. If the crack is still visible, drill a 1.6mm (0.0625″) hole at the end of the crack to stop the crack from continuing.
  4. Finish the grooving operation by featheredging a 45 degree bevel on all sides of the grooved surface area. Blow out all dust from the repair area.
  5. Cut a piece of fiberglass mat large enough to cover the “U” grooved area. On a clean surface, mix equal parts of epoxy part A and B with a plastic squeegee until a uniform color is observed. Mixing should take about 30 seconds.
  6. Apply epoxy to the fiberglass mat with the plastic squeegee, wetting the fiberglass mat on both sides.
    1. Position the patch over the area to be repaired, applying pressure with the squeegee to work out all entrapped air pockets.
    2. Smooth and level the mixture, leaving it a bit higher than the paint surface.
    3. Apply masking tape over the repair area and let harden for a minimum of 15 minutes.
  7. Remove the masking tape and sand the excess material from the repair area with 220 grit or finer sandpaper on an orbital sander. Feather the repair area into the original paint surface with 600 grit sandpaper or finer.
  8. Blow out all dust from the repair area. If the repair is “wavy,” high, low or contains porosity, repeat Step 6.
  9. Apply primer and topcoat as necessary to the repair area.

SMC PROTECTION

CAUTION:TO PREVENT FURTHER “STAR CRACKING” AFTER THE PAINT AND/OR SMC FENDER HAS BEEN SERVICED, THE UNDERSURFACE OF THE FENDER MUST BE PROTECTED. THIS SERVICE CONSISTS OF INSTALLING A SPLASH SHIELD TO THE INNER FENDER AREA TO PROVIDE A BARRIER TO KEEP TIRE-THROWN STONES FROM CRACKING THE PAINT OR THE SMC FENDER. REFER TO THE FOLLOWING STEPS TO INSTALL THE INNER FENDER PROTECTION.

  1. Remove the five (5) upper fender-to-body attaching bolts.
  2. Secure the rear fender Splash Shield (F6TZ-16326-AA) in place.
  3. Install the five (5) new bolts included with the splash shield and tighten to 7-11 N-m (5-8 lb-ft).
  4. Repeat Steps 1-3 for the other side.

PART NUMBERPART NAME
(Obtain Locally)DOMINION SURE SEAL – SMC Rigid Repair Filler A & B – 4006-XRF (2 – 8 Ounce Tubes)
(Obtain Locally)3M Rigid Parts Repair Material – 05899 (2 – 5 Ounce Tubes)
(Obtain Locally)CERTAINTEED Or OCF Fiberglass Cloth
F6TZ-16326-AASplash Shield (2 Req’d.)

OTHER APPLICABLE ARTICLES:

NONE

SUPERSEDES:

96-12-10

WARRANTY STATUS:

Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage For 1992-97 Model Year Vehicles, Base Warranty Coverage For All Other Model Year Vehicles

OPERATIONDESCRIPTIONTIME
980115AInstall Fender Shields – Both0.4 Hr.
Repair Sheet Molding Composite (SMC) Cracks And RepaintActual Time

DEALER CODING

BASIC PART NO.CONDITION CODE
1632601

OASIS CODES:

106000, 111000


Copyright 1998 Ford Motor Company