Bronco L6-300 4.9L VIN Y 1-bbl (1983)
Cross-Member: All Technical Service Bulletins
Frame/Crossmember - Snapping/Popping Noise
Article No. 94-8-13
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FRAME - # 1 CROSSMEMBER - RIVET REPLACEMENT
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NOISE - "POPPING/CREAKING" SOUNDS - FRAME # 1 CROSSMEMBER
LIGHT TRUCK:
1980-94 BRONCO, F-150-350 SERIES
1988-94 F SUPER DUTY, F-47
This TSB article is being republished in its entirety to add certain 1992/94 model year vehicles, to revise the nut specified in the article and its torque
specification, and to expand the diagnostic and repair procedures contained in the article.
ISSUE:
A "popping/creaking" sound may come from the area of the # 1 crossmember attachment to the left frame rail. This occurs because of a slip/stick motion
at a loose rivet in the lower flange of the frame near the steering gear. The rivet could be either a standard cold head rivet in light duty applications or a
"huck" rivet, which has the appearance of a large "pop" Civet.
ACTION:
Use the following diagnostic procedure to determine if the noise is originating in this rivet area. If so, replace the rivet with a nut, bolt and washer
assembly. The revised parts increase the clamp load at the joint, minimizing the motion that causes the noise. Refer to the following procedure for
service details.
SOURCES OF VARIOUS FRONT UNDERBODY NOISES:
Various front underbody noises may originate from several different sources. Several noises have been misdiagnosed as # 1 crossmember rivet
"pop/creak" because the noise tends to propagate to the shock tower area and the shock tower area acts as an amplifier such that the noises all appear to
be coming from that area. Other underbody areas that produce similar noises include:
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loose or improperly seated shock tower rivets
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loose or misaligned transmission crossmembers
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loose radius arm brackets
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loose axle pivot brackets
Other service bulletins have been published to address the proper repair of these concerns.
DESCRIPTION OF # 1 CROSSMEMBER NOISES:
"Pop/creak" - A metal-to-metal rubbing motion which slip/sticks when a twist is induced into the frame.
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 stress the frame joints, so that any frame noise is more likely to be
repeatable in the garage.
b.
Test the following situations:
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Can the noise be duplicated while stationary and on dry pavement by repeatedly turning the steering wheel from steering stop to
steering stop?
