Drive Pinion: Disassembly

WARNING: This page is about a different car, the 2003 Ford Pickup and 2003 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

Remove the axle assembly. Refer to Axle Assembly .
Remove the differential housing cover and drain the lubricant from the rear axle.
- Clean the gasket material from the differential housing cover and the differential housing.

NOTE: An inspection can find the cause of the concern and determine the resolution.

Carry out the following before disassembly.
- Remove all the lubricant from the internal parts of the conventional differential assembly or Trac-Lok® differential assembly. Visually inspect the parts for wear and damage.
- Rotate the differential assembly to check for any roughness, indicating damaged bearings or gears.
- Check the differential ring gear and pinion teeth for signs of scoring, abnormal wear, nicks or chips.
- Use a magnet to search for hidden heavy metal particles indicating component damage.
  
  Fig 1: Removing Differential Housing Cover
  Courtesy of FORD MOTOR CO.

CAUTION: The differential ring gear and pinion must be clean and dry to obtain an accurate reading.

NOTE: Measure the differential ring gear and pinion backlash at three equally spaced points around the ring gear.

Using the special tools, measure the differential ring gear and pinion backlash.
- The backlash specification cannot vary more than 0.05 mm (0.002 in) between points checked. A larger variation of backlash indicates gear or case runout concerns.
  
  Fig 2: Measuring Differential Ring Gear And Pinion Backlash Using Special Tools
  Courtesy of FORD MOTOR CO.
Remove the axle shafts. Refer to REAR DRIVE AXLE/DIFFERENTIAL-DANA S135 .

CAUTION: Note the position of the mating letters stamped vertically and horizontally on the bearing caps and the differential housing before removing the bearing caps.

Fig 3: Removing Bolts And Bearing Caps

Courtesy of FORD MOTOR CO.

Remove the bolts and the bearing caps.

CAUTION: Do not spread the differential housing more than specified.

Fig 4: Spreading Differential Housing To Specifications Using Special Tools

Courtesy of FORD MOTOR CO.

CAUTION: It will be necessary to use large pry bars to remove the differential assembly from the differential housing. Do not damage the differential ring gear when carrying out this step.

CAUTION: Mark or tag the differential bearing cups, indicating from which side they were removed.

Using the special tools, spread the differential housing to specifications, then remove the Dial Indicator Gauge with Holding Fixture.
Remove the differential assembly with the bearing cups.
- Remove the special tool after removing the differential assembly.
- Inspect the differential bearing cups for deep scores, galling, and spalling.
  
  Fig 5: Removing Differential Assembly With Bearing Cups
  Courtesy of FORD MOTOR CO.

CAUTION: Mark or tag the outboard spacers indicating from which side they were removed.

Remove the outboard spacers.
- Inspect the spacers for nicks, bending, or grooved conditions.
  
  Fig 6: Inspecting Spacers For Nicks, Bending Or Grooved Conditions
  Courtesy of FORD MOTOR CO.

CAUTION: Index-mark the pinion flange to the pinion shaft prior to removal.

Fig 7: Removing Pinion Lock Nut And Washer Using Suitable Tool To Prevent Flange From Turning

Courtesy of FORD MOTOR CO.

Using a suitable tool to prevent the flange from turning, remove the pinion lock nut and washer.
Using the special tool, remove the pinion flange.

Fig 8: Removing Pinion Flange Using Special Tool
Courtesy of FORD MOTOR CO.

NOTE: There are drive pinion preload shims on the spline end of the pinion. These shims can stick to the pinion, the pinion bearing or they can fall out of the differential housing. Collect and keep the shims for reassembly.

Fig 9: Taping Pinion Out Of Pinion Bearing Cup Using Soft Faced Hammer And Special Tool

Courtesy of FORD MOTOR CO.

Using a soft faced hammer and the special tool, tap the pinion out of the pinion bearing cup and remove it through the rear of the differential housing.
Using the special tools, remove and discard the pinion seal.

Fig 10: Removing Pinion Seal Using Special Tools
Courtesy of FORD MOTOR CO.

CAUTION: Do not nick the differential housing bore.

Fig 11: Removing Outer Pinion Bearing Cup Using Special Tools

Courtesy of FORD MOTOR CO.

Using the special tools, remove the outer pinion bearing cup.
Using the special tools, remove the inner pinion bearing cup.

Fig 12: Removing Inner Pinion Bearing Cup Using Special Tools
Courtesy of FORD MOTOR CO.
Using the special tools, remove the inner pinion bearing.

Fig 13: Removing Inner Pinion Bearing Using Special Tools
Courtesy of FORD MOTOR CO.

NOTE: Discard the drive pinion position shim if bent or nicked. If discarding the shim, measure and record the shim thickness.

Remove the oil slinger, if equipped, and the drive pinion position shim.

CAUTION: Do not disassemble the Trac-Lok® differential assembly or the Truetrac® differential assembly. Discard the entire assembly if worn or damaged.

Carry out the following after disassembling the axle:
- Thoroughly clean all parts.
- Inspect all parts for damage and wear.
- Clean the inside of the differential case before assembly. For Truetrac® differentials, submerge the entire differential assembly in a suitable solvent to wash away contaminates from within the housing.

NOTE: Differential bearings shims are available in thicknesses of 0.762, 0.787, 0.813, 0.838, 0.864, 0.889, and 0.914mm (0.030, 0.031, 0.032, 0.033, 0.034, 0.035, and 0.036 in).

NOTE: If damaged, install new differential bearing shims.

NOTE: Install new differential bearings and cups if removing the bearings from the differential case.

Using the special tools, remove the differential bearings.
- Tag the selective outboard spacers to identify the side from which they were removed. If the differential bearings are removed, add the bearing shims to the spacers for the appropriate side.
  
  Fig 14: Removing Differential Bearings Using Special Tools
  Courtesy of FORD MOTOR CO.

NOTE: Use a vise with brass jaws or wood blocks.

Place the differential case in a vise.

CAUTION: Do not damage the anti-lock speed sensor ring when removing the differential ring gear. If removing the anti-lock speed sensor ring, discard it and install a new one.

NOTE: Always use new bolts upon reassembly.

Fig 15: Removing Ring Gear Bolts

Courtesy of FORD MOTOR CO.

Remove the ring gear bolts. Leave four bolts loosely assembled, 90 degrees apart.
Tap each bolt head alternately with a rawhide or plastic hammer to loosen the differential ring gear. Remove and discard the bolts. Remove the differential ring gear.

Fig 16: Taping Bolts Head Alternately With Rawhide Or Plastic Hammer
Courtesy of FORD MOTOR CO.
If necessary, remove the anti-lock speed sensor ring with a soft-faced hammer. Discard the anti-lock sensor ring.

Fig 17: Removing Anti-Lock Speed Sensor Ring With Soft-Faced Hammer
Courtesy of FORD MOTOR CO.
Using a small drift, drive out the differential pinion shaft lock pin.

Fig 18: Driving Out Differential Pinion Shaft Lock Pin Using Small Drift
Courtesy of FORD MOTOR CO.
Using a drift, remove the differential pinion shaft.

Fig 19: Removing Differential Pinion Shaft Using Drift
Courtesy of FORD MOTOR CO.
To remove the differential side gears and the differential pinion gears, rotate the differential side gears. The differential pinion gears will turn to the opening in the differential case.

Fig 20: Rotating Differential Side Gears To Removing Differential Side Gears And Differential Pinion Gears
Courtesy of FORD MOTOR CO.
Remove the differential pinion gears and the differential pinion thrust washers behind the differential pinion gears.
Lift out the differential side gears and the differential side gear thrust washers.