Diagnostic chart of suspension noise locations and conditions

TSB 97-03-10 Frame Noise
Publication Date: FEBRUARY 3, 1997
IF THE IMAGE IS TOO SMALL, click it.

LIGHT TRUCK:
1980-96 BRONCO, F-150, F-250 LD
1980-97 F-250 HD, F-350
1988-97 F SUPER DUTY, F-47

This TSB article is being republished in its entirety to include vehicles built through the 1997 model year and to update the Transmission Crossmember Service Procedure.

ISSUE:
A "popping/creaking" sound may come from the area of the front frame or suspension brackets. This may occur because of a slip/stick motion at a loose rivet or bolt in a frame crossmember or a suspension bracket (radius arm, spring tower, spring shackle, etc.).

ACTION:
Use the following Diagnostic Procedure to determine the location of the noise. Replace the suspected fastener(s) by referring to the following Repair Procedure for details.


SOURCES OF VARIOUS FRONT UNDERBODY NOISES

Various front underbody noises may originate from several different sources and are often difficult to locate and diagnose. Common noise locations include:

> #1 (engine) crossmember rivets - primarily the rivet or "huck fastener" at the lower left front, behind the steering gear
> loose or improperly seated spring shock tower rivets/bolts
> loose or misaligned transmission crossmembers
> loose or improperly seated front leaf spring bracket rivets
> loose radius arm brackets
> loose axle pivot brackets

Other underbody areas that produce similar noises include:
> transfer case skid plate
> leaf spring bushings
> steering intermediate shafts
> shock bolts
> bumper brackets
> brakes

Other Service Bulletins have been published to address the proper repair of these concerns.


DIAGNOSTIC PROCEDURE

1. INTERVIEW THE CUSTOMER

a. Understand the customer's description of the noise and of the conditions under which it is heard.

b. Road test the vehicle with the customer to fully understand where, how, and when the noise occurs.

2. DUPLICATE THE NOISE CONCERN

a. Drive the vehicle around for at least 15 minutes to warm-up and exercise the frame joints so that any frame noise is more likely to be repeatable in the garage or on the road.

b. Identify the conditions in which the noise is repeatable. Does the noise occur:
> While parked and turning the wheels lock-to-lock?
> Only when driving?
> While going straight over bumps?
> While on a lift with the suspension unloaded?
> Only when the brakes are applied?

c. Identify the general location of the noise. Can you "feel" the noise in the floorboard or the steering wheel? Refer to Figure 9 for likely locations for the noise.

NOTE:
USE CHASSIS EARS AND/OR A STETHOSCOPE TO DETERMINE THE LOUDEST POINT OF THE NOISE. IF THE NOISE IS REPRODUCIBLE WHEN STATIONARY, PUT THE VEHICLE ON A DRIVE-ON LIFT AND "FEEL" FOR ANY MOVEMENT OR VIBRATION AT THE JOINTS.

Click "Next" beside the image above to continue.

See also:
http://www.nloc.net/vbforum/gen-1-lightnings/209927-frame-off-resto-225k-mile-lighting-2.html#post1958385
. . .

Owner caption December 2006 · Photo 1393 of 5000