TSB 87-15-11 DRIVESHAFT - DOUBLE CARDAN U-JOINT - POWERTRAIN "MOAN" AT 35 TO 45 MPH/ 56 TO 72 KM/H

LIGHT TRUCK: 1983-87 BRONCO

ISSUE: A powertrain "moan" at about 35 to 45 mph (56 to 72 km/h) may be caused by high break-away torque efforts of the double cardan U-joint "moan" is more noticeable in vehicles with AOD transmission while operating in third gear or in vehicles with manual transmissions while operating in fourth gear.

ACTION: To correct this, use the following service diagnostic procedure. To determine if driveshaft replacement is required.

1. Remove rear driveshaft.
2. Check the double cardan rotation break-away torque by attaching a fish scale, or similar measuring device, to the U-joint attachment bolt hole located on the half round driveshaft yoke, see Figure 12.
3. Pull on the fish scale, or similar measuring device, until the U-joint begins to rotate. Notice the force required to revolve the U-joint.
NOTE: Rotational effort should be measured in two (2) directions. Both efforts must be within the 3-14.5 lbs. (1.4- 6.6 kg.) specification. The two (2) directions are 90~ apart and both measurements are necessary when dealing with the two (2) different axis of the U-joints that make up the double cardan joint.
4. If the break-away torque exceeds 14.5 lbs. (6.6 kg.) in either direction, tap the ears of the double cardan U-joint weld yokes with a brass hammer. This will cause the bearing cups to reseat themselves and should result in reduced U-joint rotational break-away torque efforts.
5. Recheck rotational break-away torque by repeating Steps 2 and 3.
6. If rotational break-away torque effort is within specification, reinstall driveshaft.
7. If rotational break-away torque effort is not within specification, or if the powertrain "moan" continues, install a new service driveshaft. Refer to the driveshaft application chart below for the correct service part number.

PART NUMBER PART NAME CLASS

E7TZ-4602-A Driveshaft C
E7TZ-4602-B Driveshaft C
E5TZ-4602-M Driveshaft B
E5TZ-4602-K Driveshaft B
E5TZ-4602-L Driveshaft B
EOTZ-4602-AP Driveshaft B
E3TZ-4602-AF Driveshaft R

OTHER APPLICABLE ARTICLES: 85-3-13
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual
OPERATION: SP871511A - Steps 1-6
TIME: 0.9 Hr.

OPERATION: SP871511B - Steps 1-7
TIME: 1.4 Hrs.
DLR. CODING: Basic Part No. 4602 - Code: 56

DRIVESHAFT APPLICATION CHART
Service Engineering Part Number Model . . Part Number Stamped On Shaft . . Year . . Engine . . Transmission . . Axle Ratio
E7TZ-4602-A . . . . . . . . . . . . . . . . . . . . . . . . E7TA-4602-UA . . . . . . . . . . . . . . . 1987 . . 5.0L . . . . AOD . . . . . . . . . 3.55/4.10
E7TZ-4602-B . . . . . . . . . . . . . . . . . . . . . . . . E7TA-4602-SA . . . . . . . . . . . . . . . 1987 . . 4.9L . . . . C6/M4/TOD . . . 3.08/3.55
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.0L . . . . M4 . . . . . . . . . . 3.55
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.0L . . . . C6 . . . . . . . . . . 3.55
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.8L . . . . C6 . . . . . . . . . . 3.55
E5TZ-4602-M . . . . . . . . . . . . . . . . . . . . . . . . E5TA-4602-ACA . . . . . . . . . . . . . 1986 . . 5.0L . . . . AOD . . . . . . . . . 3.55
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1985 . . 5.0L . . . . AOD . . . . . . . . . 3.55
E5TZ-4602-K . . . . . . . . . . . . . . . . . . . . . . . . E5TA-4602-AEA . . . . . . . . . . . . . 1986 . . 4.9L . . . . TOD/M4/C6 . . . . 3.50
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.0L . . . . M4 . . . . . . . . . . . 3.50
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.8L . . . . C6/M4 . . . . . . . . 3.50
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1985 . . 4.9L . . . . M4/TOD . . . . . . 3.00/3.50 (9")
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.0L . . . . M4 . . . . . . . . . . . 3.50
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.8L . . . . C6 . . . . . . . . . . . 3.50
E5TZ-4602-L . . . . . . . . . . . . . . . . . . . . . . . . E5TA-4602-AFA . . . . . . . . . . . . . . 1986 . . 4.9L . . . . TOD . . . . . . . . . 3.08
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.0L . . . . AOD . . . . . . . . . . 4.11
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1985 . . 4.9L . . . . C6/M4/TOD . . . . 3.08/3.55
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.0L . . . . AOD . . . . . . . . . . 4.11
EOTZ-4602-AP . . . . . . . . . . . . . . . . . . . . . . EOTA-4602-GC . . . . . . . . . . . . . . 1984 . . 5.8L . . . . M4/TOD/C6 . . . . 3.50/4.11
E3TZ-4602-AF . . . . . . . . . . . . . . . . . . . . . . . E3TA-4602-MB . . . . . . . . . . . . . . 1984 . . 4.9L . . . . M4/TOD/C6 . . . . 3.08/3.55
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.0L . . . . M4/TOD/C6 . . . . 3.55
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1983 . . 4.9L . . . . M4/SROD/C6 . . . 3.08/3.55
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.0L . . . . M4/SROD/C6 . . . 3.08/3.55
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.8L. . . . M4/SROD/C6 . . . 3.55

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