Ford 2003 Mustang Workshop Manual page 497

Do not drop assembled halfshafts. The impact will cut the boots from the inside without
evidence of external damage.
Inspect all machined surfaces and splines for damage.
Wheel and Tire Balancing, Rear
WARNING: Do not balance the rear wheels and tires while mounted on the vehicle.
Possible tire disintegration, differential or halfshaft failure can result, causing personal injury
or extensive component damage. Use an off-vehicle wheel and tire balancer only.
Hoisting
CAUTION: Use a frame-contact hoist only. Vehicle or component damage can result if
other types of hoists are used.
Never raise the vehicle using the halfshafts as lift points.
Undercoating and Rustproofing
During undercoating and rustproofing procedures, protect the boots from the coating materials.
Foreign materials on the rubber boots will cause extreme advanced wear.