Center Support Bearing Noise

Fig. 5 Front U-joint Retaining Bolts & Straps:

Fig. 6 Driveshaft Center Support Bearing Retaining Bolts:

A ``howling'' noise from the driveshaft during cold initial take-off in either two or four wheel drive mode may be caused by the driveshaft center support bearing. The noise will become less noticeable as the bearing warms up during vehicle operation. This condition can be corrected by installing a new design bearing as follows. The bearing must be properly supported during removal and installation.
1. Mark U-joints for assembly reference.
2. Remove front U-joint retaining bolts and straps, Fig. 5.
3. Slide driveshaft toward rear of vehicle, then remove rear U-joint retaining bolts and straps from the tube yoke flange.
4. Slide driveshaft toward front of vehicle, then remove center support bearing retaining bolts, Fig. 6. Do not allow splined shafts to contact each other with excessive force.
5. Tape U-joint bearing cups to hold them in place, then remove the driveshaft.
6. Mark front and rear driveshaft position for assembly reference.
7. Remove bearing retaining bolts and straps, then separate front and rear driveshafts.
8. Mount driveshaft with center support bearing in a soft-jawed vise, then remove driveshaft yoke.
9. Remove driveshaft yoke using a suitable two-jaw puller (part No. T70P-4221-A or equivalent).
10. Mount driveshaft in a press with the yoke nut installed flush with end of shaft.
11. Remove center support bearing using bearing removal tool (part No. D79L-4621-A or equivalent).
12. Install new center support bearing (part No. E73Z-4800-B). Engine ``V'' section points toward coupling shaft.
13. Mount driveshaft in a soft-jawed vise.
14. Align reference marks, then install driveshaft yoke and retaining nut. Torque nut to 100--120 ft. lbs.
15. Remove driveshaft from vise, then align reference marks and position driveshaft to rear yoke.
16. Apply suitable locking compound to bearing retaining bolts, then install the bearing strap and bolts. Torque bolts to 15-17 ft. lbs.

Fig. 7 Driveshaft Alignment:

17. Ensure outermost ends of driveshaft assembly are positioned as shown, Fig. 7, then install driveshaft at rear torque tube flange, ensuring U-joint is in its original position. If driveshaft is not in line, a low speed shudder will result.
18. Apply suitable locking compound to bearing retainer nuts, then install the bearing straps and bolts. Torque bolts to 15-17 ft. lbs.
19. Position front U-joint, then apply suitable locking compound to bearing retaining bolts and install the bearing straps and bolts. Torque bolts to 15-17 ft. lbs.
20. Apply suitable locking compound to center support bearing retaining bolts, then install the bearing and bolts. Torque bolts to 23-30 ft. lbs.