1988 Ford B700 recalls

BECAUSE OF A MACHINING INCONSISTENCY, THERE IS A HIGH PISTON-TO-BALL CONTACT ANGLE IN THE STEERING GEAR WORM DRIVE. THIS CONTACT CAUSES THE BALLS TO TRY TO ROTATE ON TWO DIFFERENT ROLLING RADII AT TWO DIFFERENT SPEEDS, CAUSING THE BALL TO DAMAGE THE CONTACT SURFACES OF THE PISTON AND SPINDLE DURING STATIC OR LOW SPEED MANEUVERS INVOKING FULL OR NEAR FULL TURNS.

STEERING ABILITY DETERIORATES AND EVENTUALLY STEERINGLOCKUP OCCURS DURING THESE LOW SPEED MANEUVERS RESULTING IN LOSS OF STEERINGCONTROL AND AN INCREASED RISK OF VEHICLE ACCIDENT.

REPLACE BENDIX C300N STEERING GEARS WITH NEW GEARS.

SYSTEM: ELECTRICAL SYSTEM; BATTERY. VEHICLE DESCRIPTION: MEDIUM DUTY SCHOOL BUS CHASSIS EQUIPPED WITH HYDRAULIC BRAKES, TILT HOODS, 5.9L, 6.6L OR 7.6L DIESEL ENGINES OR 6.1L OR 7.0L GASOLINE ENGINES AND ORIGINALLY SOLD OR CURRENTLY REGISTERED IN CONNECTICUT, ILLINOIS, INDIANA, MAINE, MASSACHUSETTS, MICHIGAN, NEW HAMPSHIRE, NEW JERSEY, NEW YORK, OHIO, PENNSYLVANIA ,RHODE ISLAND, VERMONT, AND WISCONSIN. THE BATTERY POWER JUNCTION BLOCK MOUNTED ON THE RIGHT FENDER APRON, WHICH SERVES AS AN ELECTRICAL CONNECTION POINT FOR SEVERAL ENGINE COMPARTMENT SYSTEMS, IS SUSCEPTIBLE TO ROAD SPLASH. THE TERMINALS AT THE JUNCTION BLOCK CAN EXPERIENCE CORROSION AND CAN FRACTURE, CAUSING LOSS OF ELECTRICAL POWER AND ENGINE SHUTDOWN.

ENGINE SHUTDOWN, LOSS OF POWER STEERING ASSIST, OR LOSS OF HYDRAULIC BRAKE BOOST CAN OCCUR WHICH MAY RESULT IN LOSS OF VEHICLE CONTROL AND AN ACCIDENT.

DEALERS WILL REPLACE THE JUNCTION BOX, MAIN POWER TERMINAL THE STARTER OR STARTER RELAY AND TERMINALS AT THE EXISTING JUNCTION BLOCK. THE WIRING OF THE HYDRAULIC BRAKE CIRCUIT WILL ALSO BE MODIFIED BY BYPASSING THE JUNCTION BLOCK. THE NEW TERMINALS WILL BE MADE FROM AN ALLOY MATERIAL MORE RESISTANT TO SALT CORROSION.

THE STEERING GEARS HAVE AN IMPROPERLY MACHINED SNAP RING GROOVE. THIS CAN CAUSE A FRACTURE OF THE SNAP RING WITH SUBSEQUENT DAMAGE TO THE RECIRCULATING BALL GUIDE TUBE. ALSO, THE O-RING SEAL IN VEHICLES BUILT AFTER FEBRUARY 1988 DOES NOT MEET SPECIFICATIONS AND IS INADEQUATE, CAUSING INTERIOR LEAKAGE AROUND THE O-RING / GLIDE RING SEAL IN THE STEERING GEAR.

THE FRACTURE OF THE SNAP RING RESULTS IN INCREASING DETERIORATION OF THE ABILITY TO TURN THE VEHICLE TO THE RIGHT. THE DRIVER WOULD EXPERIENCE INCREASED STEERING EFFORTS OR A "CRUNCHY" FEELING AT THE STEERING WHEEL. THE INADEQUATE O-RING SEAL CAUSES MOMENTARY REDUCTIONS IN POWER STEERING ASSIST AT LOW SPEED AND CERTAIN LEFT TURN MANEUVERS. BOTH CONDITIONS RESULT IN DECREASED STEERING ABILITY.

DEALERS WILL REBUILD THE STEERING GEAR. IF A BROKEN SNAP RING IS FOUND DURING REBUILDING, THE STEERING GEAR WILL BE REPLACED WITH A REMANUFACTURED UNIT.