Axle Shaft Seals
Axle shaft oil seals are susceptible to the same kinds of damage as axle drive pinion seals if incorrectly
installed. The seal bore must be clean and the lip handled carefully to avoid cutting or tearing it. The axle shaft
journal surface must be free of nicks, gouges, and rough surface texture.
Differential Seals
For additional information on differential seals, refer to REAR DRIVE AXLE/DIFFERENTIAL-FORD 8.8-
INCH or REAR DRIVE AXLE/DIFFERENTIAL-FORD 9.75-INCH for the rear axle or FRONT DRIVE
AXLE/DIFFERENTIAL-FORD 8.8-INCH for the front axle.
Analysis of Vibration
Few vibration conditions are caused by the front or rear axle. On a vibration concern, follow the diagnosis
procedure in Section NOISE, VIBRATION & HARSHNESS unless there is a good reason to suspect the axle.
Tires
Most vibration in the rear end is caused by tires or driveline angle.
Vibration is a concern with modern, high-mileage tires if they are not "true" both radially and laterally. They are
more susceptible to vibration around the limits of radial and lateral runout of the tire and wheel assembly. They
also require more accurate balancing. Wheel and tire runout checks, truing and balancing are normally done
before axle inspection. Refer to WHEELS & TIRES - F150 PICKUP .
Driveline Angle
Driveline angularity is the angular relationship between the engine crankshaft (6303), the driveshaft, and the
rear axle pinion. Factors determining driveline angularity include ride height, rear spring and engine mounts.
Driveline Angle
WARNING:
A vehicle equipped with a Traction-Lokohm differential will always have
both wheels driving. If only one wheel is raised off the floor and the rear
axle is driven by the engine, the wheel on the floor could drive the vehicle
off the stand or jack. Be sure both rear wheels are off the floor.
WARNING:
Do not balance the wheels and tires while they are mounted on the
vehicle. Possible tire disintegration/differential failure can result, causing
personal injury/extensive component damage. Use an off-vehicle wheel
and tire balancer only.
2003 Ford Pickup F150
2003 GENERAL INFORMATION Driveline System - General Information - F150 Pickup