1. Engage parking brake, put in first gear/park and chock from tires.
2. Raise rear of car, putting a jackstand under each side of the rear support member. Placing the front of the car on jackstands is also advised.
3. Remove rear tires.
4. Remove driveshaft (12 point 12mm).
5. Release parking brake and remove calipers.
6. Remove ABS sensors.
7. Mark position of camber adjustment flange on upper control arms relative to control arm.
8. Remove upper and lower control arm-to-spindle bolts.
9. Pull/pry spindle inboard axle stubs to release halfshafts from differential; halfshafts are not held to differential with any fasteners; once upper bolt is removed from the spindle, the halfshaft will release from differential with sufficient force applied to inboard axle stub.
10. With a floorjack under the pumpkin, unbolt and remove pumpkin from car. Keep level to minimize drainage of lube from pumpkin.
Removing Differential
11. With pumpkin over a drain tub, remover pumpkin cover and drain lube.
12. Remove the differential bearing caps; Bearing caps must be reinstalled on same side of differential as they were removed.
13. Use a long prybar to dislodge the differential. If differential is in tightly, insert prybar through window in differential and rotate pinion gear. The rotation of the pinion gear will push differential out of the axle housing as the prybar contacts the pumpkin. Note: Bearing races and differential shims must be re-installed on same side of differential as they were removed.
Removing Pinion Gear
14. Use long bar to hold pinion flange and remove the pinion nut. A piece of 3ft by 1" U-channel with two holes drilled in it for being attached to pinion flange works well.
15. Use puller to remove the pinion flange.
16. Remove pinion gear.
Installing Bearing and Shim on Pinion
17. Use feeler gauge to measure shim between pinion bearing and back of the pinion gear. The pinion shims may be used in place of feeler gauges.
18. Use race to press new bearing (with shim) onto the new pinion gear.
Note: The use of the pinion depth tool is not mentioned in these instructions. The pinion depth tool determines a reference distance between the machined seats for the differential bearing seats and the pinion gear rear bearing seat. Variations in the reference distance result from machining variations in the pumpkin, not the gear sets. It has been my experience in installing FRPP (previously Ford Motorsport) gear sets that using the same size shim on the pinion gear provides the proper pinion depth. The machined dimensions and tolerance of the FRPP pinion gears gear sets are essentially identical to those of stock Ford gears. Use of non-Ford/FRPP gears may require the use of a depth check tool as dimensions and tolerances for other brands of gear sets may be different than Ford/FRPP gear sets.
Replacing Pinion Races and Seal
19. Use seal puller to remove pinion seal.
20. Use long steel punch to remove pinion races, if replacement is necessary.
21. Use old races or race install tool to install new races; make sure that are installed to full depth of the bore in the differential.
22. Install new seal using large socket or seal installer.
Replacing Ring Gear
23. Remove ring rear bolts (6 point 3/4" ˝" drive socket); Use long rod or long ˝" drive extension through differential shaft hole to hold differential while removing bolts.
24. Using a brass punch or block of wood, tap ring gear off of differential.
25. Make sure the new ring gear and differential flange surfaces are free of debris and burrs.
26. Position new ring rear on differential with bolt holes aligned to holes in differential.
27. Use four bolts spaced evenly around the ring gear to draw the ring gear against the flange; tighten each bolts in small increments to prevent the gear from binding. If all of the four bolts cannot be started, place ring gear in hot water for a few minutes to expand it.
28. Remove four ring gear bolts, apply Loctite to all ring gear bolts and tighten.
29. Torque bolts in alternating fashion to 70 ft-lbs.
Installing Pinion Gear
30. Install a new crush sleeve on the pinion gear, lube the bearing and install pinion gear into the differential.
31. Place pinion flange and nut on the pinion.
32. Attach long bar to pinion flange and tighten nut just enough to remove play in the gear.
33. Remove bar and rotate pinion gear several turns.
34. Use 1/4 drive torque wrench to check torque required to maintain rotation of pinion gear.
35. Re-attach bar and tighten bar about 1/16 to 1/8 turn
36. Repeat steps 34 to 46 until torque required to maintain rotation is 14 to 24 in-lbs; 16 to 20 in-lbs is best for used bearings; 20 to 24 in-lbs is best for all new bearings.
37. Remove bar when complete.
Reinstalling Differential
38. Place differential in pumpkin with passenger side race and shim also in place.
39. Install passenger side bearing cap with cast-in arrows pointing outward.
40. Snug differential cap bolts; make sure differential is not binding as bolts are tightened.
41. Install driver side race and then LIGHTLY tap shim into place with a punch; make sure differential is firmly against passenger side race and shim prior to installing driver side shim.
42. Install driver side bearing cap with arrows pointing outward.
43. Torque bolts to 70 ft-lbs.
44. Rotate differential a few turns.
Checking Set-up
45. Check backlash using dial indicator mounted to machined cover surface; dial indicator should be touching outer most part of tooth with the indicator perpendicular to tooth surface.
46. Backlash should be .008 to .012; change shims to adjust backlash, if necessary.
47. Use paint on the teeth to check pattern (primarily when using non-Motorsport gears and/or installing a new differential).
Finishing Install
48. Replace differential cover.
49. Reinstall pumpkin in car.
50. Insert and lock halfshaft inboard axle stubs in differential. Make sure they are locked in place.
51. Reattach control arms to spindles, making sure to align camber adjustment flange on upper control arms relative to control arm, as previously marked.
52. Install ABS sensors.
53. Install calipers.
54. Install driveshaft; torque to 90 ft-lbs.
55. Fill differential with lube and 4 oz. of friction modifier
56. Install tires
57. Lower car.
58. Make final check.
59. Lit'em up…well, first break in the gears for a few hundred miles first.
These
Instructions
