SAFARI

FRONT AXLE - 4

3. AUTOMATIC LOCKING HUBS DIAGNOSIS

3.1

NOTE

: In this diagnosis section, there are some

numerical call-outs (such as (1),(2) etc.). For these

call-outs refer to the exploded view.

Oil Leaks

Make sure that suspected oil leak is actually coming from

the hub. Oil leaks can originate in the axle shaft (oil seal).

An oil leak from the hub can be caused by :

1. A crackedor porous or improper fitment of protective

end cap.

2. Damaged ormissing "O" rings.

3. Incorrectly installed or damaged sealing ring (10)

between the End Cap and outer clutch housing and

wheel hub.

Does not Engage or Disengage

Beforedisassemblingof a lockinghub, besure theproblem

is caused by the hub and not by another component in

the drive train.

Other possible problems include :

Transfer casenot engagingor disengaging front axle shaft.

Viscosity of front differential lubricant toohigh (i.e. due to

cold weather).

Front differential pre-load too high.

Seized front axle shaft bearing.

3.2 AUTOMATIC LOCKING HUBS DIAGNOSIS

IMPORTANT

: When diagnosing a "ratcheting" hub,

remember that thenoisyhub is "NOT" always thedefective

one . it depends on whether the hubs have just been

disengaged. Let's examine why.

If only onehubdisengages after 2-wheel drive is selected,

the faulty hub transmits the wheel rotation to the axle

shaft.Themechanical situation is like a conventional axle

raisedoff the ground.The axle shaft drives the deferential

pinions through the side gear.The ring gear and cage are

not turning, so theother sidegear andaxle shaft aredriven

in the opposite direction to the first one. The axle shaft

tries to engage the hub against the directionof thewheel

rotation, causing the noise. fromthe hub. In this case, the

faulty hub is not making the noise. The non-noisy hub

should be checked. If 4 wheel drive is selected and only

one hub engages, there may not be any noise from the

hub, depending on the malfunction.The only symptom

mightbea lossof driveat thathub. If thehub is "ratcheting"

in 4-wheel drive, it should be inspected.

Possible Causes

A broken or missing drag sleeve 4 tanged washer can

cause problems in 2-or 4-wheel drive.

A broken or missing washer will allow the drag sleeve to

rotate with the brake band. If the hubs are not engaged,

the brake band is unable to lock on the drag sleeve and

initiate the locking action of the clutches. If the hubs are

engaged, thebrakeband cannot be released to allowthe

clutch gear to disengage.

ABrokenormissingbrakeband (24) cannot lock the inner

cage toengage thehubor beunlockedby theouter sleeve

to allow the clutch gear to disengage.

If both brake and tangs are touching the centre post of

the outer sleeve, there cannot be proper locking or

unlockingactionof thebrakebandthroughthemovement

of the inner cage (21) and outer cage (20). The Center

post of the outer cage and the window of the inner cage

move relative to each other when the hub is locking or

unlocking. If the cages are not rotating freely over each

other, the hubmay fail to engage or disengage.

A sticking clutch gear can cause the hub to bind in either

the engage or the disengage position. A broken return

spring will cause the hub to remain in the engaged

position.

Ineachcase, thedefective component shouldbe replaced

with the correct genuine part or assembly.