Frame/Crossmember - Snapping/Popping Noise
Article No. 94-8-13^ FRAME - # 1 CROSSMEMBER - RIVET REPLACEMENT
^ 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:
^ loose or improperly seated shock tower rivets
^ loose or misaligned transmission crossmembers
^ loose radius arm brackets
^ 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:
^ Can the noise be duplicated while stationary and on dry pavement by repeatedly turning the steering wheel from steering stop to steering stop?
^ Can the noise be repeated while on the hoist without the suspension loaded by repeatedly turning the steering wheel from steering stop to steering stop?
Typically, the twist in the frame can be induced by turning the steering wheel back and forth from steering stop to steering stop to duplicate the noise at the # 1 crossmember attachment. IF THE NOISE IS NOT DUPLICATED UNDER ONE OF THESE SITUATIONS, INVESTIGATE OTHER AREAS FOR THE NOISE BEFORE PROCEEDING TO REPAIR THE # 1 CROSSMEMBER RIVET.
3. INSPECT FRAME BOLTS FOR PROPER INSTALLATION TORQUE:
a. Inspect and tighten all front end components which bolt to the frame to confirm they are at the proper torque. This includes, but is not limited to:
^ Radius arm bracket bolts - 135 +/- 20 N-m (100 +/- 15 lb.ft.)
^ Axle pivot bracket bolts (torques vary by model - refer to the appropriate light truck Service Manual for proper torque specifications)
^ Bumper bracket bolts - (refer to the appropriate light truck Service Manual for proper torque specifications)
b. Inspect the transmission crossmember for proper alignment and bolt torques. If misaligned:
^ Loosen all transmission crossmember fasteners (including to the transmission).
^ Lift the transmission to remove any load on the crossmember.
^ Lift and reposition the transmission crossmember to be centered on the frame attachment holes.
^ Tighten all frame fasteners to the 63 +/- 9 N-m (46 +/- 7 lb.ft.).
^ Lower the transmission and tighten fasteners to 95 +/- 15 N-m (70 +/- 11 lb.ft.).
4. TEST DRIVE THE VEHICLE
Road test the vehicle again to duplicate the concern. If the noise is still present, continue.
5. INSPECT THE FRAME RIVETS
a. Repeat Step 2 to duplicate the noise in the garage.
b. Use a stethoscope or chassis ears to isolate the area of the chassis that the noise appears to be originating from. Areas to check include the shock tower rivets and all # 1 crossmember rivets.
6. SERVICE THE VEHICLE
a. If the noise appears to be from the lower left-front # 1 crossmember fastener, follow the procedure outlined below.
b. If the noise appears to be coming from another rivet (other than the lower left front # 1 crossmember rivet), refer to TSB 93-6-10 for the proper rivet repair procedure.
LOWER LEFT FRONT # 1 CROSSMEMBER RIVET REPLACEMENT:
NOTE:
THIS SERVICE PROCEDURE DOES NOT APPLY TO STEERING GEAR LINER REPLACEMENT. REFER TO TSB 90-11-10 FOR STEERING GEAR LINER REPAIR PROCEDURE.
1. Remove damaged or loose COLD HEAD RIVETS:
a. Drill a 1/8" (3.175 mm) hole through the rivet.
b. Redrill the same hole through the shank of the rivet with a 3/8" (9.525 mm) drill.
c. Remove the rivet head with an air chisel.
d. Drive out the rivet with a punch and hammer.
2. Remove damaged or loose "HUCK" RIVETS:
a. Use a flat chisel and hammer (or air chisel) to split the exposed collar of the huck fastener, Figure 1.
b. Knock the rivet pin out of the blind side with a 1/4" (6.35 mm) drift punch and hammer, Figure 2.
c. Cut the rivet's head off with a hammer and flat chisel, Figure 3.
d. Knock the sleeve out of the blind side with a 3/8" (9.525 mm) drift punch and hammer, Figure 4.
CAUTION:
REMOVAL OF THE FASTENER WITH A CUTTING TORCH IS NOT RECOMMENDED BECAUSE OF PROBABLE DAMAGE TO THE FRAME STRUCTURE.
3. Line ream the existing hole through the liner, frame flange and crossmember to 9/16" (14.228 mm), Figure 5.
4. Install a 9/16" Grade 8 nut (34990-S4), bolt (58698-S2) and washer (44880-S2), with nut/washer on the bottom, Figure 6.
a. Push the bolt into place using a brazing rod to hold the bolt.
b. Slide the bolt into the opening between the front face of the crossmember and frame liner.
c. Tighten the nut to 140 4-3 lb.ft. (190 4-4 N-m) and tack weld the nut to the bolt after tightening.
CAUTION:
DO NOT WELD THE NUT/WASHER TO THE FRAME.
PART INFORMATION
OTHER APPLICABLE ARTICLES: 91-11-10
SUPERSEDES: 91-25-18
WARRANTY STATUS:
Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage For 19 2-94 Models, Basic Warranty Coverage For All Other Models
OPERATION DESCRIPTION TIME
940813A Perform Diagnostics And 1.9 Hrs.
Replace Rivet
DEALER CODING
BASIC PART NO. CONDITION CODE
5005 56
OASIS CODES: 305000, 390000, 702000, 702100