Shadow Convertible L4-153 2.5L SOHC (1994)
Bumper: All Technical Service Bulletins
Front Bumper - Vibration At Idle in Reverse
NO.: 18-11-93
GROUP: Driveability
DATE: Jul. 23, 1993
SUBJECT:
Idle Quality When In Reverse
NOTE:
THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 18-18-91. CHANGES ARE HIGHLIGHTED WITH **ASTERISKS**.
MODELS:
**1989-1994**
(AP) Sundance/Shadow
NOTE:
THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH 2.2L/2.5L ENGINES & AUTOMATIC TRANSMISSIONS.
SYMPTOM/CONDITION:
Some of the subject vehicles may exhibit undesirable vibration characteristics while at idle with the transmission in reverse gear. This condition may be
the result of contact between the front bumper and one or more of the adjacent components. These vehicles are equipped with a "tuned" front bumper
system that is designed to reduce the amount of vibration transmitted to the passenger compartment. If contact with adjacent components occurs, the
effectiveness of the bumper system may be diminished and cause objectionable passenger compartment vibration.
DIAGNOSIS:
1.
To verify the customer complaint, bring the engine to full operating temperature, and then allow the engine to idle in reverse with the parking
brake applied.
2.
Observe the level of vibration from the driver's seat. (Typically the vibration can be increased by operating the air conditioning.)
3.
Once the complaint has been verified, check for loose body components, front bumper damage, and/or collision damage. If nothing is found,
perform the following repair procedure.
REPAIR PROCEDURE:
This repair procedure involves checking the clearance between the front bumper fascia and adjacent body components and making any necessary
adjustments.
1.
Insert a 3 x 5 inch card, business card, or similar "gauge" between the top of the front bumper fascia and the adjacent grille and front fenders.
Move the gauge from side-to-side to determine if the bumper fascia is pressing against the grille and/or front of either fender.
2.
If the fascia is in contact with this area, lower the bumper using the bolts attaching the bumper beam to the energy absorbing units (refer to the
applicable service manual for bumper component removal and installation). Keep the gap between the bumper fascia and the upper body to a
minimum and as uniform as possible.
3.
Check the idle quality complaint by bringing the engine up to operating temperature and then allow the engine to idle in reverse with the parking
brake applied. The amount of engine vibration sensed from the driver's seat should be significantly less than prior to repositioning the bumper. If
the idle quality is still objectionable, continue on to the next step.
4.
Insert the gauge between the top of the front bumper fascia and the fenders near the wheel well openings. Move the gauge from side-to-side to
determine if the bumper fascia is pressing against either fender. If the fascia is in hard contact with either fender, remove the bumper/beam
assembly, adjust the fender mounted slider brackets downward 5/64 inch (2 mm) and install the bumper/beam assembly. During installation,
maintain a minimum and an even as possible gap between the bumper fascia and the upper body across the entire length of the bumper facia. Make
additional adjustments to the bumper mounting and to the mounting of the fascia slider brackets if necessary. Verify that the vibration is at an
acceptable level.
POLICY:
Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
