Ford F150 Pickup. Instruction — part 643

Fig. 15: Positioning Special Tool On Wheel Hub Or Axle Flange Face
Courtesy of FORD MOTOR CO.

2. Rotate the hub or flange one full turn and note the maximum and minimum readings. The difference

between the maximum and minimum readings will be the total face runout. The runout must not exceed
0.127 mm (0.005 inch).

Drive Pinion Stem and Pinion Flange

Check the pinion flange runout when all other checks have failed to show the cause of vibration.

One cause of excessive pinion flange runout is incorrect installation of the axle drive pinion seal. Check to see if
the spring on the seal lip has been dislodged before installing a new ring gear and pinion.

Coupling Shaft Center Bearing Alignment - SuperCab Long Bed Only

2003 Ford Pickup F150

2003 GENERAL INFORMATION Driveline System - General Information - F150 Pickup

Vehicle noise and vibration can be caused by a dislocated/failed driveshaft center bearing support rubber
insulator, contaminated driveshaft center bearing support (4800) or excessive compression of the rubber
insulator. Refer to DRIVESHAFT & UNIVERSAL JOINTS - F150 PICKUP .

Bearing Shimming

Drive-away shudder is the predominant symptom associated with driveline angles condition on vehicles with
two-piece driveshafts. Drive-away shudder can usually be corrected by shimming down the driveshaft center
bearing bracket.

If the drive-away shudder cannot be corrected by shimming down the driveshaft center bearing bracket, check
the driveline angles as described in the General Procedures portion of this section.

Halfshafts, Front Wheel

z

Inspect the boots for evidence of cracks, tears, or splits.

z

Inspect the underbody for any indication of grease splatter near the boots outboard and inboard locations.
This is an indication of boot/clamp damage.

Axle Noise

The noises described as follows usually have specific causes that can be diagnosed by observation as the unit is
disassembled. The initial clues are the type of noise heard during the road test.

Gear Howl and Whine

Howling or whining of the ring gear and pinion is due to an incorrect gear pattern, gear damage or incorrect
bearing preload.

Bearing Whine

Bearing whine is a high-pitched sound similar to a whistle. It is usually caused by worn/damaged pinion
bearings, which are operating at driveshaft speed. Bearing noise occurs at all driving speeds. This distinguishes
it from gear whine which usually comes and goes as speed changes.

NOTE:

New constant velocity (CV) joints must not be installed unless disassembly and
inspection reveals unusual wear. Refer to AXLE SHAFTS (4WD) - F150 .

NOTE:

Inspect the boots for indentations ("dimples") in the boot convolutions.
Indentations must be removed.

NOTE:

Before disassembling the axle to diagnose and correct gear noise, eliminate the
tires, exhaust, trim items, roof racks, axle shafts (4234) and wheel bearings as
possible causes. Follow the diagnostic procedures in NOISE, VIBRATION &
HARSHNESS - F150 PICKUP .

2003 Ford Pickup F150

2003 GENERAL INFORMATION Driveline System - General Information - F150 Pickup

As noted, pinion bearings make a high-pitched, whistling noise, usually at all speeds. If however there is only
one pinion bearing that is worn/damaged, the noise may vary in different driving phases. New pinion bearings
must not be installed unless they are scored or damaged or there is a specific pinion bearing noise. A
worn/damaged bearing will normally be obvious at disassembly. Examine the large end of the rollers for wear.
If the pinion bearings original blend radius has worn to a sharp edge, a new pinion bearing must be installed.

A wheel bearing noise can be mistaken for a pinion bearing noise. On 4x2 vehicles, check the wheel bearing for
a spalled cup, and spalled/damaged rollers. Install a new wheel bearing if any of these concerns are detected.

Fig. 16: Inspecting Wheel Bearing
Courtesy of FORD MOTOR CO.

If the wheel bearing is damaged, the roller surface on the axle shaft may also be damaged. Install a new axle
shaft if any damage is detected.

NOTE:

A low-pitched rumble normally associated with a worn/damaged wheel bearing
can be caused by the exterior luggage rack or tires.

2003 Ford Pickup F150

2003 GENERAL INFORMATION Driveline System - General Information - F150 Pickup

Fig. 17: Inspecting Axle Shaft
Courtesy of FORD MOTOR CO.

On 4x4 vehicles, check the wheel bearing for rotating smoothness and end play. Install a new wheel bearing as
necessary.

Chuckle

Chuckle that occurs on the coast driving phase is usually caused by excessive clearance between the differential
gear hub and the differential case bore.

Damage to a gear tooth on the coast side can cause a noise identical to a chuckle. A very small tooth nick or
ridge on the edge of a tooth can cause the noise.

2003 Ford Pickup F150

2003 GENERAL INFORMATION Driveline System - General Information - F150 Pickup