Navajo 4WD V6-4.0L OHV (1991)
Suspension Strut / Shock Absorber: Customer Interest
Engine Mount/Exhaust System - Vibration
Bulletin No.: 004/96
Issued: 06/27/96
Revised:
Category
R
Applicable Model/s
1991 - 94 Navajo
Subject:
VIBRATION/SHAKE ON SMOOTH ROADS (+50MPH) VIBRATION/SHAKE OVER BUMPS (-45MPH)
APPLICABLE MODELS/VINS
1991-94 Navajo
DESCRIPTION
Some vehicles may experience a vibration/shake felt in the seat and/or floor at speeds above 50 MPH and peaking near 65 MPH. This concern does not
depend on engine RPM and occurs in all driving modes (i.e. acceleration, cruise and deceleration). An "after shake" concern may also exist when driving
over a bump at less than 45 MPH. This concern may lessen after tire balancing or replacement, but is not completely eliminated.
The cause of this concern may be the result of the movement frequency of the engine aligning with the tire rotation frequency.
Customers complaining of this concern should have the vehicle inspected according to the instructions in this bulletin and if necessary, have the revised
engine mounts (left and right), rear axle-to-frame lateral shock absorber kit and main silencer tail pipe assembly installed.
NOTE:
^
Service Managers should place a copy of this bulletin in the NVH manual.
^
This bulletin does not apply to vehicles with engine block heaters. Inadequate clearance exists for new engine mount installation with block
heaters installed.
^
This repair will not compensate for the following:
a)
Out-of-round or out-of-balance wheel/tire assemblies.
b)
Vibration resulting from abnormal or irregular tire wear.
c)
Other tire/wheel quality or out-of-specification issues.
INSPECTION PROCEDURE
1.
Verify that the vibration/shake occurs in all driving modes including neutral coast.
^
If the concern occurs as specified, proceed to step 2.
^
If the concern does not occur as specified, refer to the NVH manual for trouble-shooting and repair instructions.
2.
Visually inspect the tires for abnormal or irregular wear patterns. If necessary, replace the tire(s) with the original equipment size and type.
3.
Set the tire pressure to the specification listed on the calibration label located on the driver's side B pillar.
4.
Check the wheel/tire balance, repair as necessary.
5.
Test drive the vehicle.