See Figure 1
Other than the preload spring, pinion shaft and gears, and the clutch packs, the overhaul of this unit is identical to that of the conventional differential.
For removal of these components, see the Adjustment procedures immediately following.
CLUTCH PACK PRELOAD ADJUSTMENT
See Figures 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16
This adjustment can be made with the unit in the vehicle. The axle shafts, however, must be completely removed.
- Using a punch, drive the S-shaped preload spring halfway out of the differential case.
- Rotate the case 180 degrees. Hold the preload spring with pliers and tap the spring until it it removed from the differential.
- Using gear rotator too T80P-4205-A, or equivalent, rotate the pinion gears until the gears can be removed from the differential. A 12-inch (305mm) extension will be needed to remove the gears.
- Remove the right and left side gear clutch pack, along with any shims, and tag them for identification.
- Clean and inspect all parts. Use only acid-free, non-flammable cleaning agents. Use a lint-free cloth to wipe the parts dry. Replace any damaged parts.
- Assemble the clutch packs (without the shims) on their side gears. Coat all friction plates with limited-slip lubricant such as Ford Additive Friction Modifier, or equivalent, meeting EST-M2C118-A specifications.
- Place the base portion of the Traction-Lok Clutch Gauge T87T-4946-A, or equivalent, in a vise. Install the clutch pack and side gear, without the shims, over the base.
- Install the tool's disc over the base and on top of the clutch pack.
- Install the top portion of the tool over the disc and base stud.
- Install the tool's nut and tighten it to 60 inch lbs. (6.7 Nm).
- Using feeler gauges, determine the distance between the tool and the clutch pack. This will be the thickness of the necessary shim.
- Install the right side gear, clutch pack and new shim into the differential case. Repeat this for the left side.
- Place the pinion gears and thrust washers 180 degrees apart on the side gears. Install tool T80P-4205-A or equivalent.
- Rotate the tool until the pinion gears are aligned with the pinion shaft hole. Remove the tool.
- Hold the S-shaped preload spring at the differential case window. Use a plastic mallet to drive the spring into position. Check the spring for damage.
BENCH TORQUE TEST
See Figure 17
This test must be made any time the differential has been removed or adjustments have been made.
Use the locker tool in set T59L-4204-A, or equivalent, to check the torque required to rotate one side gear while the other is held stationary. If the original clutch plates are used, breakaway torque should be at least 20 ft. lbs. (27 Nm).
With new clutch plates, the torque required to keep the side gear turning will fluctuate.