Rear Differential ...... Adjustments

Rear Differential


When repairing a rear differential one thing that must be checked is the Crown & Pinion gear backlash. Backlash should be checked before disassembly and reset to the same setting if you are planning to use the same gear set.
Backlash is measured using a magnetic base dial indicator which reads the rocking back and forth travel on the Crown Gear. This adjustment is very important because a high or low backlash setting changes the gear pattern on the differential.
The backlash is adjusted by moving the threaded side bearing adjusting rings which moves the crown closer or farther away from the pinion gear. A new differential gear set is usally adjusted between .005 - .015 in. while a used gear set is adjusted between .015 - .025 in.


The final backlash setting on your gear set depends on the gear tooth pattern [by painting on a substance that shows gear tooth contact, I use copper never-seize compound] With some resistance you roll the crown and pinion gears around so the contact will give you an idea if the backlash or pinion gear depth has to be adjusted.
These are the 2 most important adjustments on a rear differential.