Tuff Country 14056 - GM 07-13 Silverado 1500 4wd 4 lift kit - Manual (Page 9)

26. Remove the hydraulic floor jacks from under the front dif-
ferential.
27. Working on the driver side, check and double check to
make sure that the rear portion of the front differential does
not contact the rear lower control arm pocket. If contact
occurs, more of the differential will need to be cut out.
28. Re-connect the 4WD wiring harness back to the front dif-
ferential. Special note: Take special care not to kink the
wiring and make sure that the harness is tightly secured.
29. Re-install the drive line back to the front differential using
the OE hardware. Make sure to use loctite and torque to 35
ft lbs.
30. Re-install the rear cross member to the driver and pas-
senger side rear lower control arm drop pockets using the
OE hardware. Make sure to use loctite and torque to 55 ft
lbs.
31. Locate the new upper control arms. Locate (8) poly
bushings and (4) sleeves from hardware bag 14056PL.
Install the new bushings and sleeves into the new upper
control arms. Special note: Make sure to use a fair
amount of lithium or moly base grease before installing
the new bushings and sleeves into the control arms.
This will increase the life of the bushing as well as help
prevent squeaking.