Bronco L6-300 4.9L VIN Y 1-bbl (1983)
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Can the noise be repeated while on the hoist without the suspension loaded by repeatedly turning the steering wheel from steering stop
to steering stop?
Typically, the twist in the frame can be induced by turning the steering wheel back and forth from steering stop to steering stop to duplicate the noise at
the # 1 crossmember attachment. IF THE NOISE IS NOT DUPLICATED UNDER ONE OF THESE SITUATIONS, INVESTIGATE OTHER AREAS
FOR THE NOISE BEFORE PROCEEDING TO REPAIR THE # 1 CROSSMEMBER RIVET.
3.
INSPECT FRAME BOLTS FOR PROPER INSTALLATION TORQUE:
a.
Inspect and tighten all front end components which bolt to the frame to confirm they are at the proper torque. This includes, but is not
limited to:
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Radius arm bracket bolts - 135 +/- 20 N-m (100 +/- 15 lb.ft.)
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Axle pivot bracket bolts (torques vary by model - refer to the appropriate light truck Service Manual for proper torque specifications)
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Bumper bracket bolts - (refer to the appropriate light truck Service Manual for proper torque specifications)
b.
Inspect the transmission crossmember for proper alignment and bolt torques. If misaligned:
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Loosen all transmission crossmember fasteners (including to the transmission).
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Lift the transmission to remove any load on the crossmember.
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Lift and reposition the transmission crossmember to be centered on the frame attachment holes.
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Tighten all frame fasteners to the 63 +/- 9 N-m (46 +/- 7 lb.ft.).
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Lower the transmission and tighten fasteners to 95 +/- 15 N-m (70 +/- 11 lb.ft.).
4.
TEST DRIVE THE VEHICLE
Road test the vehicle again to duplicate the concern. If the noise is still present, continue.
5.
INSPECT THE FRAME RIVETS
a.
Repeat Step 2 to duplicate the noise in the garage.
b.
Use a stethoscope or chassis ears to isolate the area of the chassis that the noise appears to be originating from. Areas to check include the
shock tower rivets and all # 1 crossmember rivets.
6.
SERVICE THE VEHICLE
a.
If the noise appears to be from the lower left-front # 1 crossmember fastener, follow the procedure outlined below.
b.
If the noise appears to be coming from another rivet (other than the lower left front # 1 crossmember rivet), refer to TSB 93-6-10 for the
proper rivet repair procedure.
LOWER LEFT FRONT # 1 CROSSMEMBER RIVET REPLACEMENT:
NOTE:
THIS SERVICE PROCEDURE DOES NOT APPLY TO STEERING GEAR LINER REPLACEMENT. REFER TO TSB 90-11-10 FOR
STEERING GEAR LINER REPAIR PROCEDURE.
1.
Remove damaged or loose COLD HEAD RIVETS:
a.
Drill a 1/8" (3.175 mm) hole through the rivet.
b.
Redrill the same hole through the shank of the rivet with a 3/8" (9.525 mm) drill.
c.
Remove the rivet head with an air chisel.
d.
Drive out the rivet with a punch and hammer.
2.
Remove damaged or loose "HUCK" RIVETS:
