(Gears Gone Wild - continued)

Install the driveshaft flange and the new pinion nut (supplied with FMS gearsets.) The nut requires about 150 lb-ft of torque to crush the sleeve. You want to achieve about 25 in-lb. of frictional resistance when turning the pinion. Begin by torquing the nut to 120 lb-ft. Then turn the pinion and check resistance. Apply torque in 10 lb-ft increments until the correct resistance is achieved.	Getting the torque on the nut is tough because the pinion will spin. Here we've put a bolt in the driveshaft flange and are using a wrench on the bolt to counter the breaker bar. The foot ads in stability. Whatever it takes, get that crush sleeve crushed.
The new 3.73:1 gear assembly is set into the carrier. Be sure the races are on the bearings before setting into place.	Install the bearing caps to their respective sides based on your earlier markings and torque to 75-85 lb-ft.
Using a dial indicator and magnetic base John checks for proper backlash. The dial indicator touches a tooth on the ring gear. Rock the gear gently until it just contacts the pinion gear tooth. This is the "backlash", or space between the two gears. Ford calls for .0005-.0010". If you are out of spec shims are required against the carrier bearings to move the ring gear towards the pinion or away depending on weather clearance is excessive or too little.	Backlash and gear mesh can also be checked by using gear paint on a section of ring gear. Rotate the gear and observe the contact pattern on the ring gear teeth. Use shims to move the gear assembly to the left or right depending on whether the contact is inward on the tooth or outward. The Ford or Chilton manuals give good instructions on how to interpret the patterns.
The axles can now go back into the housing assembly.	Reinstall the axle retaining c-clips.
Drive the pinion shaft through the differential and reinstall the retaining bolt. Torque the bolt to 20-30 lb-ft.	Fill the case with two quarts of gear oil and use a 4 oz. bottle of Ford friction modifier (C8AZ-19B546-A), especially if you rebuilt the clutch packs.
Clean and reinstall the differential cover. A bead of silicone is preferable to a paper gasket.	The housing assembly is rolled back under the car and control arms, springs, calipers and sway bar go back in place.
Before roasting the rubber, allow the gear-set to break in by driving for 15-20 minutes at 2500 rpm, then stopping and allow the gears to cool completely.