Ford F150 Pickup. Instruction - part 577

Fig. 105: Measuring Ring Gear Backlash 
Courtesy of FORD MOTOR CO. 

10. If a zero backlash condition occurs, add 0.51 mm (0.020 inch) to the RH side and subtract 0.51 mm 

(0.020 inch) from the LH side to allow backlash indication. Check the backlash. Repeat step 9 .  

11. To increase or decrease the backlash, remove the bearing caps and install a thicker shim or a thinner shim 

as shown. 

z

If the backlash is not within specification, correct by increasing the thickness of one differential 
bearing shim and decreasing the thickness of the other differential bearing shim by the same 
amount.  

 

2003 Ford Pickup F150 

2003 DRIVELINE/AXLES Rear Drive Axle/Differential - Ford 8.8-Inch Ring Gear - F150 Pickup

  

Fig. 106: Installing Thicker Or Thinner Shim 
Courtesy of FORD MOTOR CO. 

12. Rotate the differential several times to make sure the differential bearings are correctly seated. 

 

2003 Ford Pickup F150 

2003 DRIVELINE/AXLES Rear Drive Axle/Differential - Ford 8.8-Inch Ring Gear - F150 Pickup

  

Fig. 107: Rotating Differential To Ensure Correct Seating Of Differential Bearings 
Courtesy of FORD MOTOR CO. 

13. Using the special tool, recheck the backlash. 

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If the backlash is within specification, go to step 14 . If the backlash is not within specification, 
repeat step 9 .  

 

2003 Ford Pickup F150 

2003 DRIVELINE/AXLES Rear Drive Axle/Differential - Ford 8.8-Inch Ring Gear - F150 Pickup

  

Fig. 108: Rechecking Backlash 
Courtesy of FORD MOTOR CO. 

14. Remove the bearing caps and bolts. 

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To establish differential bearing preload, increase both left and right shim sizes by the specification 
shown in the illustration.  

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Using the special tool, make sure that the differential bearing shims are fully seated and the 
assembly turns freely.  

 

2003 Ford Pickup F150 

2003 DRIVELINE/AXLES Rear Drive Axle/Differential - Ford 8.8-Inch Ring Gear - F150 Pickup