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Another offering from the Toolbox, we hope this feature of the magazine is useful to you. This one looks at a typical
maintenance job of changing the front wheel bearings on the T3 VW. We hope to bring you many more tails from the toolbox in the future. Rod has many years experience working on many types of VW and is aware of the safety requirements, if you have any doubts what so ever leave it to the professionals. |
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Jack up the offending corner and make safe, these vehicles are heave and good axle stands are a necessity. Now off with the wheel and prise off the cap covering the axle stub nut. If you are working on the Left front wheel then the speedo' cable must be released from the cap by removing its circlip before prising the cap off. Before proceeding to remove the hub and brake disk assembly the brake calliper must be removed and swung away. This is a little tricky as the hydraulic pipe is fixed to a bracket on the top ball joint, however the pipe joint can be freed from the bracket without undoing the pipe by rotating a small clip. Remove the brake pads by tapping out the retaining pins towards the centre of the vehicle, pulling out the pads and retainer plates, these should be replaced in the same location on re-assembly. The calliper is held in place by two large bolts, remove these noting which came from where, as they are different! A second pair of hands is useful to hold the calliper up whilst the hub nut is removed and the hub pulled clear. Temporarily screw one bolt loosely into place to hold the calliper whilst the bearings are replaced in the hub.
Replacing the bearings, firstly drive out the old ones with a drift. There are two slots in the inner flange against which the bearing rest, these allow a drift to be placed against the bearing edge. Equal strikes to each side in turn will knock the bearing out. The inner (larger) one can be forced out taking the grease seal with it or the seal can be prised out first, the outer comes away similarly with no seal present. Two large pieces of wood about 100mm square by 400mm long placed side by side on a sound flat surface with a 100mm gap between make an excellent 'anvil' for this process. Refitting the bearings should only be done after all traces of old grease and dirt have been removed from the inner part of the hub. With a clean hub, place it on your wooden anvil, place the outer ring of a bearing in the hub and carefully drive it into place with a drift. If you have a socket that as small enough to fit inside the hub but large enough to press on the edge of the bearing then use this to drive the bearing home to its seating. Use a similar method with the other bearing ensuring that both are hard against their inner flanges, again check for cleanliness of the parts. Place the bearing race and inner ring inside the large bearing so that the grease seal can be pressed into place, in these hubs it should be pressed in until its outer face is flush with the outer face of the hub. Now apply ALL the grease that should have been packed with your new bearing kit. This should be within the cavity between the bearings, around its sides to allow clear replacement onto the stub axle. The inner components of the small outer bearing can be replaced as the hub is put into place on the stub axle this prevents accidentally dropping it in the dirt!
Re-assembly is, as they say in all good manuals, the reverse of disassembly. However please note the following. Use a new nut to retain the hub, screwing it up to a point where the large washer with the internal tab can just be moved with the end of a screwdriver. Lock it in place as the original was, usually by peening its locking edge into the grove in the stub axle. Also note the two differing bolts that hold the brake calliper in place, don't mix them up as forcing the shouldered one into the wrong hole will destroy the calliper. Don't forget to replace the clip for the brake pipe in its correct location. If the Left front wheel don't forget the speedo' cable circlip.
Also note that the brake pedal will have excess travel on the first use after this operation as the pads are returned to their normal operating position.
The above procedure is very similar for many Volkswagens (and others) with disc brakes on non-driven front wheels, hub nut locking designs vary as do brake calliper mountings and pipe fittings but principals remain the same. |
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