What is the preload on the pinion bearing and the backlash on the crownwheel and pinion inside the rear differential of a 1997 ford explorer 4 wheel drive?
The shim between the inner bearing and the pinion is critical
and if it's lost you need special tools to set the pinion depth.
replace the bearings and seal with an new crush sleeve thighten the
pinion nut until the sleeve crushes and you can't move the pinion
up and down. Then very slowly tighten the pinion nut checking the
rotational torque. You will need an inch pound torque wrench, when
the preload is correct it should take between 20-25 inch pounds of
torque to rotate the pinion. If you get it too tight you need to
replace the crush sleeve and start over. Proper bearing preload and
gear mesh are critical.