Thunderbird V6-232 3.8L SC (1989)
Wheel Hub: Customer Interest
Brakes - Roughness/Pulsation/Steering Wheel Shake
Article No.
92-4-3
02/12/92
BRAKES - ROUGHNESS, PULSATION OR STEERING WHEEL SHAKE - ANTI-LOCK (4 WHEEL DISC) AND BASE BRAKE (REAR DRUMS)
SYSTEMS
FORD:
1989-92 THUNDERBIRD
LINCOLN-MERCURY:
1989-92 COUGAR
ISSUE:
Brake roughness, pulsation and steering; wheel shake, may occur because of uneven rotor wear. Two major causes of uneven rotor wear are...
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Abrasive brake pads (semi-metallic material)
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Hub or rotor high and low spots (improper orientation during assembly)
Usually these vehicles appear to be corrected by just installing new pads and rotors. However, they can repeat the condition after some time in service
unless proper attention is given to...
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Front Brake Pads
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Hub/Rotor "Stacked" Runout
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Tire Wear And Balance
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Rear Brake Rotors Or Rear Brake Drums
ACTION:
Check the front brake pads, hub/rotor "stacked" runout, tire wear/balance and rear rotors/drums. Refer to the following procedure for service details.
FRONT BRAKE PADS
1.
Replace the front brake pads with ONLY the new asbestos pads (F1SZ-2001-A).
CAUTION:
USING METALLIC FRONT BRAKE PADS (FOSZ-2001-A) WILL CAUSE UNEVEN ROTOR WEAR.
2.
Refer to the 1992 Thunderbird/Cougar Service Manual, Section 06-03, for service details.
HUB/ROTOR "STACKED" RUNOUT CHECK
If the assembled system (new rotor installed on hub) indicates more than .002" (.051 mm) total runout (TIR), it will cause excessive thickness variation
in the rotor as mileage accumulates by wearing the high spots off the rotor. Excessive thickness variation in the rotor causes brake pulsation and steering
wheel shake.
High system runout (TIR) is caused by...
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Rust/contamination trapped between the hub and rotor mounting surface
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Rotor or hub (high and low spots) not being properly oriented during assembly
1.
Clean the hub area that will contact the new rotor. Remove rust build-up and debris.
2.
Install a new rotor (FOSZ-1L104-A for 1989/90 vehicles and F1SZ-1125-A for 1991/92 vehicles) on the hub.
a.
Secure it with at least four (4) lug nuts.
b.
Tighten the four (4) lug nuts to 10 Lb-Ft (13 N.m) for testing.
