47 FRONT AXLE - 4 X 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.
RkJQdWJsaXNoZXIy MTIwNTUz