TM 10-3930-659-34 5-17. DIFFERENTIAL ASSEMBLY MAINTENANCE (Con’t). 17. Remove lifting device from rear differential assembly (20). 18. Using dial indicator, check differential preload. Differential preload must be 0.002-0.004 in. (0.050-0.101 mm). 19. Rotate rear differential assembly (20) a minimum of two times. Using a mechanical force gage and twine wrapped around center of rear differential assembly, measure rolling drag torque. Steady pulling force should be 2.1-7.8 lb (9.3-34.7 N) force. 20. Add shims (24) to bearing quills (21) to reduce rolling drag torque or remove shims from bearing quills to increase rolling drag torque. NOTE • Perform steps 21 through 25 for front differential only. • Perform steps 25 through 27 for rear differential only. 21. Apply silicone sealing compound (Item 17, Appendix B) to edge of front differential cover (19). 22. Install  front  differential  cover  on  front  differential  housing  (14)  with  ten  washers  (15)  and  screws  (16).  Torque screws to 55 lb.-ft. (75 N•m). 23. Install new preformed packing (18) and plug (17) on front differential cover (19). NOTE Position breather tube so that notch in bottom is parallel to axle shaft. 24. Install breather tube (13), new preformed packing (12), and breather (11) into front differential housing (14). TA708382 5-172