Ford F150 Pickup. Instruction - part 650

Fig. 37: Positioning Special Tool As Shown 
Courtesy of FORD MOTOR CO. 

If the flange runout exceeds 0.25 mm (0.010 inch), remove the pinion flange, reindex the flange one-half 
turn on the pinion, and reinstall it. Refer to REAR DRIVE AXLE/DIFFERENTIAL-FORD 8.8-INCH 
or REAR DRIVE AXLE/DIFFERENTIAL-FORD 9.75-INCH or FRONT DRIVE 
AXLE/DIFFERENTIAL-FORD 8.8-INCH for the flange removal and installation procedures. 

8. Check the runout again. If necessary, rotate the flange until an acceptable runout is obtained. If the flange 

runout is still more than 0.25 mm (0.010 inch), install a new pinion flange. 

 

2003 Ford Pickup F150 

2003 GENERAL INFORMATION Driveline System - General Information - F150 Pickup

  

Fig. 38: Rotating Flange Until An Acceptable Runout 
Courtesy of FORD MOTOR CO. 

9. If excessive runout is still evident after installation of the pinion flange, install a new ring and pinion. 

Repeat the above checks until the runout is within specifications.  

10. Install the driveshaft. Refer to DRIVESHAFT & UNIVERSAL JOINTS - F150 PICKUP .  

Tooth Contact Pattern Check - Gearset 

1. To check the gear tooth contact, paint the gear teeth with the special marking compound. A mixture that 

is too wet will run and smear; a mixture that is too dry cannot be pressed out from between the teeth.  

2. Use a box wrench on the ring gear bolts as a lever to rotate the ring gear several complete revolutions in 

both directions or until a clear tooth contact pattern is obtained.  

3. Certain types of gear tooth contact patterns on the ring gear indicate incorrect adjustment. Incorrect 

adjustment can be corrected by readjusting the ring gear or the pinion.  

Contact Pattern Location 

In general, desirable ring gear tooth patterns must have the following characteristics: 

 

2003 Ford Pickup F150 

2003 GENERAL INFORMATION Driveline System - General Information - F150 Pickup

  

z

Drive pattern on the drive side ring gear well centered on the tooth.  

z

Coast pattern on the coast side ring gear well centered on the tooth.  

z

Clearance between the pattern and the top of the tooth.  

z

No hard lines where the pressure is high.  

Acceptable ring gear tooth patterns for all axles. 

Fig. 39: Identifying Ring Gear Tooth Patterns For All Axles 
Courtesy of FORD MOTOR CO. 

Correct backlash with a thinner pinion position shim required.

 

2003 Ford Pickup F150 

2003 GENERAL INFORMATION Driveline System - General Information - F150 Pickup

  

Fig. 40: Identifying Correct Backlash With A Thinner Pinion Position Shim Required 
Courtesy of FORD MOTOR CO. 

Correct backlash with a thicker pinion position shim required. 

Fig. 41: Identifying Correct Backlash With A Thicker Pinion Position Shim Required 
Courtesy of FORD MOTOR CO. 

Correct pinion position shim that requires a decrease in backlash.

 

2003 Ford Pickup F150 

2003 GENERAL INFORMATION Driveline System - General Information - F150 Pickup