Town Car V8-302 5.0L (1987)
Wheels: All Technical Service Bulletins
Body/Driveline - Vibration/Body Boom/Shake
VIBRATION - DRIVELINE - BODYBOOM,
Article No.
HARSHNESS AND SHAKE
88-6-19
FORD:
1986-87 CROWN VICTORIA
LINCOLN-MERCURY: 1986-87 GRAND MARQUIS, LINCOLN TOWN CAR
ISSUE:
Driveline vibration, body boom, harshness or shake at speeds between 35 and 65 mph (56 and 105 km/h) may be caused by one or more
vehicle components. The areas that contribute to these concerns are wheel runout, driveshaft and U-joints, body-to-frame alignment, rear
shock absorbers, rear axle housing or rear axle ring and pinion gears.
ACTION:
To correct this, use the following diagnostic procedure to determine which areas require attention.
NOTE:
The first step in correcting these concerns is performing a thorough road test.
1.
A VISIBLE shake between 35 and 65 mph (56 and 105 km/h) in the steering wheel, steering column, floor pan, seats and the front sheet metal may
be serviced by referring to the 1987 Car Shop Manual, Volume A, Section 18, "HIGH SPEED SHAKE DIAGNOSIS", Step A8 and the following
wheel runout procedure.
a.
With a roller point installed on the dial indicator, measure wheel rim radial runout.
b.
If measurement exceeds .045" (1.14 mm), install a new wheel E2AZ-1007-A (15" x 6") or E6AZ-1007-A (15" x 6.5")
NOTE:
Match the high point of the tire to the low point of the wheel assembly.
c.
Balance the wheel and tire assembly.
d.
Install the wheel on the vehicle.
2.
A vibration or shudder FELT between 40 and 50 mph (64 and 80 km/h) along with a "rumbling" or "booming" NOISE may be serviced by
inspecting and correcting the driveshaft U-joints for correct movement. Refer to the 1987 Car Shop Manual, Volume A, Section 18.
NOTE:
A U-joint that is free in one direction but tight in the other can cause low speed vibration.
3.
A vibration FELT between 50 and 65 mph (80 and 105 km/h) along with a "drone", "humming", or "booming" NOISE may be serviced by
balancing the driveshaft on the vehicle. Refer to the 1987 Car Shop Manual, Volume A, Section 18, Steps F1 through F4. This will compensate for
excessive companion flange runout and driveline imbalance.
4.
A power deck lid closure mechanism that pulls down too much on the deck lid or a deck lid that is excessively tight will increase the vehicle
sensitivity to driveline NOISE. This can be serviced by performing the adjustment procedures outlined in the 1987 Car Shop Manual, Volume A,
Section 44-12.
5.
On Lincoln Town Cars only, make sure the aluminum-backed self-adhesive mastic panels that are used to lessen the effects of driveline vibration
are secured to the center of the rear fender quarter panels. To make sure the bond is okay, use a screwdriver handle to apply a load to the entire
mastic panel.
6.
Harshness FELT between 20 and 65 mph (32 and 101 km/h) when the vehicle passes over tar strips and expansion joints can be serviced by
inspecting and correcting the body-to-frame alignment. Refer to TSB 85-24-15 for detailed service information.
NOTE:
When inspecting the body mounts, the vehicle must be supported by the front lower control arms and the rear axle. The rear axle must
be supported by a moveable two (2) post hoist or adjustable safety stands.
7.
If the vibration has not been reduced to an acceptable level after performing Steps 1 through 6, inspect the shock absorbers for sticking and
binding using the following procedure.
a.
Remove the rear shock absorbers.
b.
Collapse the shock absorbers by hand and allow them to extend by themselves from the internal pressure. If the shock absorbers do not
extend freely, obtain new shock absorbers, E5AZ-18125-A.
c.
Install the shock absorbers.
