Ford F150 Pickup. Instruction - part 644

Clean the gear tooth nick or ridge with a small grinding wheel. If the damaged area is larger than 3.2 mm (1/8 
inch), install a new gearset. 

To check the ring gear and pinion, remove as much lubricant as possible from the gears with clean solvent. 
Wipe the gears dry or blow them dry with compressed air. Look for scored or damaged teeth. Also look for 
cracks or other damage. 

If either gear is scored or damaged badly, a new ring gear and pinion must be installed. 

 

2003 Ford Pickup F150 

2003 GENERAL INFORMATION Driveline System - General Information - F150 Pickup

  

Fig. 18: Inspecting Ring Gear 
Courtesy of FORD MOTOR CO. 

If metal has broken loose, the axle housing must be cleaned to remove particles that will cause damage. At this 

 

2003 Ford Pickup F150 

2003 GENERAL INFORMATION Driveline System - General Information - F150 Pickup

  

time, if any other parts in the axle housing are damaged, new parts must also be installed. 

Knock 

Knock, which can occur on all driving phases, has several causes including damaged teeth or gearset. 

Fig. 19: Inspecting Ring Gear & Pinion 
Courtesy of FORD MOTOR CO. 

In most cases, one of the following conditions will occur: 

1. A gear tooth damaged on the drive side is a common cause of the knock. This can usually be corrected by 

grinding the damaged area. 

 

2003 Ford Pickup F150 

2003 GENERAL INFORMATION Driveline System - General Information - F150 Pickup

  

Fig. 20: Inspecting Ring Gear & Pinion 
Courtesy of FORD MOTOR CO. 

2. The knock is also caused by excessive end play in the axle shafts. Up to 0.762 mm (0.030 inch) is 

allowed in semi-float axles. The frequency of the knock will be less because the axle shaft speed is slower 
than the driveshaft.  

Clunk 

Clunk is a metallic noise heard when the automatic transmission is engaged in REVERSE or DRIVE. The noise 
may also occur when throttle is applied or released. It is caused by backlash somewhere in the driveline or loose 
suspension components; it is felt or heard in the axle. Refer to TOTAL BACKLASH CHECK . 

Additionally, clunk may be heard upon initial drive-away. This occurs as engine torque shifts vehicle weight, 
forcing changes in driveline angles, preventing the driveshaft slip-yoke from sliding on the output shaft. To 
correct this condition, lubricate the slip-yoke splines. Refer to DRIVESHAFT & UNIVERSAL JOINTS - 

NOTE:

Measure the end play with a Dial Indicator with Bracketry and not by feel.

 

2003 Ford Pickup F150 

2003 GENERAL INFORMATION Driveline System - General Information - F150 Pickup