REAR WHEEL ALIGNMENT- PROCEDURE AND SPECIFICATIONS

VEHICLES AFFECTED: 1984 Pontiac Fiero

The Pontiac Fiero is designed with independent rear suspension that is service adjustable, making four-wheel alignment possible. This is different from all other Pontiac models, both FWD and RWD, which have solid rear axles with fixed alignment.

Rear wheel alignment on Fiero can be performed by backing the car onto a two-wheel aligner, or by using the new, more efficient four-wheel aligners. If the vehicle must be backed onto alignment equipment and equipment does not compensate for rear toe measurements, toe-in will read on the equipment as toe-out.

Whenever a tire wear or handling condition is encountered, rear alignment should be measured and reset if necessary. Excessive toe-in or toe-out can cause irregular or premature wear. For best tire wear, toe-in should always be set to low end of the specification.

SUSPENSION ALIGNMENT SPECIFICATIONS

COLUMN (1) (2) (3) CONDITION VEHICLE HELD AT ALIGNMENT HEIGHT - SEE TRIM HEIGHT SECTION BELOW (A)

TO AS SHIPPED SERVICE ALIGN FACTORY CHECKING AUDIT Front ----- CASTER +5.0 DEG +/- 2.0 DEG (B) +/-5.0 DEG +/- 2.0 DEG (B) (DEGREES)

CAMBER (DEGREES) +/-.5 DEG +/-.8 DEG +/-.5 DEG +/-.8 DEG

TOE-IN (C) +/-.15 DEG +/- 1 DEG (DEGREES- +/-.30 DEG +/- .2 DEG (PER WHEEL) 1.60mm +/-1.1mm TOTAL (D) 3.2mm +/- 2.2mm

CAMBER -1.0 DEG +/-.5 DEG -1.0 DEG +/-.5 DEG (DEGREES)

TOE-IN (E) +/-.15 DEG +/- .1 DEG +/-.30 DEG +/- 2 DEG (DEGREES- TOTAL (D) PER WHEEL) 1.60mm +/- 1.1mm 3.2mm +/- 2.2mm

TO SERVICE ALIGN SETTING ------- Front ----- CASTER +/- 5.0 DEG +/- 2.0 DEG (B) (DEGREES)

CAMBER (DEGREES) +/- .5DEG +/- .8 DEG

TOE-IN (C) +/-.15 DEG +/- .05 DEG (DEGREES- 1.60mm +/- .5 mm (PER WHEEL)

CAMBER -1.0 DEG +/- .25 DEG (DEGREES)

TOE-IN (E) +/-.15 DEG +/- .05 DEG (DEGREES- 1.60mm +/- .5 mm PER WHEEL)

(A) DUE TO PROCESSING REQUIREMENTS FACTORY ALIGNMENT SETTINGS WERE MADE AT THIS HEIGHT. THIS HEIGHT WAS CHOSEN TO BE VERY CLOSE TO ACTUAL CURB HEIGHT EXPECTED IN SERVICE.

(B) LEFT AND RIGHT SIDE TO BE EQUAL WITHIN 2 DEG.

(C) STEERING WHEEL TO BE WITHIN +/- 5 DEG OF STRAIGHT AHEAD UNDER ALL CONDITIONS.

(D) ADD RIGHTT AND LEFT PER WHEEL VALUES. TOTAL TOE SHOULD BE THE VALUE CHECKED BECAUSE ACCURATE PER WHEEL VALUES RELY ON ESTABLISHING EXACTLY THE SAME VEHICLE CENTER LINE AS WHEN SETTINGS WERE MADE. EXACTLY REPEATING VEHICLE CENTERLINE IS VERY DIFFICULT. IF TOTAL TOE IS WITHIN RANGE GIVEN, RESETTING SHOULD NOT BE NECESSARY UNLESS THERE IS A COMPLAINT OF STEERING WHEEL OFF INDEX OR DOG TRACKING.

(E) IF VEHICLE MUST BE BACKED ONTO ALIGNMENT EQUIPMENT AND EQUIPMENT DOES NOT COMPENSATE FOR REAR TOE MEASUREMENTS, TOE-IN WILL READ ON THE EQUIPMENT AS TOE-OUT.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.