Front Differential Description & Operation (page 3 of 4)

 
The casing comprises two halves with machined mating faces. When assembled, the cast iron casing halves are sealed 
with a thin film of Loctite 5999 sealant and secured together with fourteen bolts. A breather tube is fitted to the casings. 
This allows a plastic tube to be fitted and routed to a high point in the engine compartment, preventing the ingress of 
water when the vehicle is wading.  
 
The RH casing is fitted with a drain plug. The front differential unit contains approximately 0.7 litre of oil for a dry fill.  
 
The differential is a conventional design using a hypoid gear layout. This employs a hypoid bevel pinion gear and crown 
wheel, with the pinion offset above the centre line of the crown wheel. This design allows for a larger pinion gear to be 
used, which has the advantages of increased gear strength and reduced operating noise.  
 
The front differential is available in three ratios. V8 and V6 petrol engine vehicles use a front differential with a final drive 
ratio of 3.73:1 and TdV6 diesel engine vehicles use a final drive ratio of 3.07:1, for vehicles with manual transmission, and 
3.54:1 for vehicles with automatic transmission. Changing the number of teeth between the crown -wheel drive gear and 

11

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Cover seal

12

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Roller bearing cup

13

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Bearing preload spacer

14

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Taper roller bearing

15

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Bolt, 10 of

16

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Differential case

17

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Roll pin

18

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Gear and pinion assembly

19

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Taper roller bearing

20

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Roller bearing cup

21

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Shim

22

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Collapsible spacer

23

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Roller bearing cup

24

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Taper roller bearing

25

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Oil seal

26

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Inner deflector

27

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Outer deflector

28

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Flange

29

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Pinion nut retainer

30

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Pinion nut

31

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Mounting bush assembly

32

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Axle mounting bracket

33

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Data label

34

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Breather tube

35

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Cap

36

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Fill plug

37

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Bolt, 3 of

38

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Taper roller bearing

39

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Bearing preload spacer

40

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Roller bearing cup

41

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Thrust washer

42

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Planet gear

43

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Shaft

44

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Sunwheel

45

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Thrust washer

46

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Mounting bush assembly