Put the jackstands on your vehicle, lift it up, then safely support and block the other wheels to stop the car from moving before you remove its front or rear wheels. At the front or back of the car, undo the lug nuts for the wheels, use jackstands to lift safely, block the other wheels first. Separate the driveshaft from its connection at the companion flange, then find a safe spot to tie it down. Twist the pinion a few turns by hand. Then measure how much torque the inch-pound torque wrench requires to turn the pinion. Record the reading for future use. Note how the pinion flange connects to the shaft, and count the thread parts showing on the shaft. Clamp down a flange holding tool or chain wrench to stop the companion flange from moving when you take out the self-locking pinion nut. Take out the nut with the pinion and let the flange slide down, using a two-jaw puller when needed but never strike or pry. Melt the old seal from its joint and throw it away. Coat the lips of the new seal with wheel bearing grease and push the greasy seal into place, pressing evenly with a seal install tool or large socket to ensure it fits directly and goes fully into the housing. Push the pinion flange into position by hand with marks on it lined up, tighten the pinion nut carefully to move the flange into place without using a hammer. Put a bead of RTV sealant around the exposed splines in the center of the flange, to keep oil inside. Then install and tighten the pinion nut until it shows the number of threads from before. Take small torques in stages to rotate the pinion, then increase pressure on the nut until your measurements fall in line with earlier results without dragging on the new oil seal. Keep tightening until the rotational torque goes up 5 in-lbs past the earlier mark, ensuring the preload falls within specification. When the maximum nut rotation doesn't reach the desired preload, take the differential apart and put in a fresh, built-in spacer. Put everything back where it was, applying the specified amount of force to every connecting screw to match factory settings. For 4WD models, you'll need two tools: one to firmly hold the companion flange still while you use another tool to loosen and take out the self-locking pinion nut. After removing the nut and flange, further assist with a two-jaw puller if the flange won't come out easily. Take the old seal out, lubricate both edges of the new seal, press wheel bearing grease inside the seal, and push it smoothly into place. Put the pinion flange in place, tightening the pinion nut when needed. Add sealant to both splines and bolt on the pinion nut while making sure you meet the proper torque. Reconnect the driveshaft to the pinion flange.
