Answer & Solution
Answer: Option
C
Solution:
Option A: Crown wheel and the sun gear
The sun (side) gears sit inside the differential case and mesh with the planet (pinion) gears to allow left–right speed difference. Any clearance here is inherent to design/manufacturing and is not where final-drive backlash is set. Therefore, backlash is not adjusted between the crown wheel and sun gear.
Option B: Sun gear and the planet gear
These gears handle the differential action only. Their small clearances ensure smooth relative motion between the two axle shafts but are not adjusted as “backlash” for the final drive. No shimming or carrier movement is performed here for backlash adjustment, so this is not the correct location.
Option C: Crown wheel and the drive pinion
The crown wheel (ring gear) meshes directly with the drive pinion to form the final-drive gearset. The backlash is intentionally adjusted at this mesh to provide a precise tooth clearance for lubrication, thermal expansion, quiet operation, and tooth life. Mechanics set this by shifting the ring gear laterally via carrier side shims/adjusters and by setting pinion depth and bearing preload. This is the standard and correct adjustment point in differentials.
Option D: Crown wheel and the planet gear
The crown wheel is bolted to and drives the differential case; it does not directly mesh with the planet (pinion) gears. The planet gears mesh with the sun gears inside the case. Since there is no crown wheel–planet gear mesh, there is no backlash adjustment here.
Conclusion: The adjustment for backlash in a differential is provided between the crown wheel and the drive pinion — Option C.
