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Front Wheel Bearing Replacement
This job is definitely not for the light-hearted. Fist time I did it, it took the best part of two days. Anyway here goes !
First jack up the front of the car and secure with axle stands. Next remove the road wheel to expose the hub, and brakes. Before the hub itself can be removed, the brake caliper has to be removed. The caliper is bolted very tightly to the bottom of the strut by two large bolts. These will also have an anti-loosen plate attached, so the first thing to do is tap the metal flaps down so you can get a socket over the bolt head. With a good heave, the bolts should loosen off. It is not necessary to disconnect the brake hose to do this job but you will need to have something to hang the caliper off the spring and keep it out of the way. I use electrical wire which is nice and strong. If you chose to undo it completely, you also need to detach the hydraulic pipe at the union with the flexible brake hose. When you do this, be prepared for the brake fluid to start gushing out. I recommend that you have to hand, a threaded end-cap to screw on over the exposed union. This will prevent a large mess ! Carefully undo the bolts on the caliper and remove the whole assembly from the car.
Next job is to remove the hub which includes the brake disc. Prise off the hub-cap and clean away the grease that is hopefully still there. To remove the large hub-retaining nut and washer, first bend and extract the split pin and the nut cover. The nut itself is not on tight and once removed, the entire hub should pull away from the car. You will see that the outer wheel bearing also falls into your hand at this stage. The inner one requires a bit more effort. That's the easy bit over with, now the fun starts !
Spend some time cleaning up the hub - it will be packed with grease that should all be removed. If you turn the hub over you will see the four bolts that hold the brake disc on. If you are replacing the disc itself, then you remove these and separate the old disk from the hub. The rear of the hub has a grease seal fitted which feels rubbery. There should be a replacement for this in the bearing kit you have bought. It can be tricky removing this. I managed to do it by slowly prising it out with two large screwdrivers. It took ages mind. When it finally pops out, you will find the inner bearing that will fall out into your hand.
When it is cleaned up again, the bearing guides will be visible. These are the metal rings that the bearing rollers sit on. They are shiny in appearance and are very hard (heat treated). The guides are matched with the bearings and must be replaced. Do not be tempted to skip this as you will end up even worse off than before.
I'll warn you now that these guides are very difficult to get out. You need a good quality hardened punch and pass it through the centre of the hub. You will just be able to touch the back of the guide. There is about 2mm of it for you to hit. Basically, you need to patiently tap away until the guide moves down. Eventually it will fall out of the hub. It is definitely much worse than it sounds ! You must be very careful not to scratch or knock the hub itself as the cast iron is very soft. Take your time and tap gently. It took about thirty minutes each guide last time I did this.
Once you have both guides out, check the place where they sit for damage caused by your tapping. Don't panic if there is; with a bit of care you can file or grind the metal down again. The new guides have to be tapped into hub which is even harder than removing the old ones. It is vital that the surface of the guides is not scratched or marked in any way otherwise you have a disaster on your hands. Therefore, you must ONLY USE BRASS for this stage. I used a bit of brass rod. Take your time getting it started off. If it is not going in straight then start again. Eventually, the guide will start to slowly move into the hub. This bit is very frustrating. Keep tapping round and round until you are sure that the guide sits tight in the hub. And of course, there are two to do.
If everything went smoothly you will be able to fit the bearings into the guides and spin the hub round on your fingers. Before fitting to the car, make sure that there are no shards of brass still in the hub centre (I had a lot and used a paint brush with turps to clean it out). Next job is to fit the rear seal. Again, this needs to be tapped gently into the back of the hub. Make sure the inner bearing is fitted first and has been thoroughly greased. Try using a block of wood to tap the seal in. It is often reluctant to go in straight but be patient. Then pack the inside hub with a suitable quality grease. The bearings should be well coated in grease so that it is worked into all the nooks and crannies.
You should now be able to re-fit the hub to the strut and fix in place. The hub-nut should be tightened using the procedure described in the service guide. The brake caliper needs re-fitting and the brake union re-attached. You will of course have to bleed the brakes to remove the air in the pipes. This procedure is described in the service guide !