Rear Wheel Bearing Replacement
This job requires some special equipment so please make sure you know what you are letting yourself in for before starting the job. It is not a particularly difficult job, but you will need access to a slide hammer to remove the half shafts from the axle, and access to a large press to change the bearings. That said, you could always take the half shafts round to a garage and get them to change the bearings for you. Before you start, make sure that you have purchased the correct wheel bearing kit, which will comprise two pieces: the bearing itself and a steel retaining ring.
To begin with, loosen the rear wheel nuts and jack up the rear of the car on the differential. Secure the car with axle stands on the axle tube. Remove the road wheel and the drum brake cover. The end of the half shaft has the 4 wheel studs on it. You will see that the hub has two round holes cut in it to allow you to put a socket through and reach the bolts that hold the half shaft retainer plate in place. These bolts are tapped into the axle case so all you need to do is loosen them off from the front. With all 4 removed it should in theory be possible to give the half shaft a good pull and it will suddenly slide out of the axle. This is unlikely to happen though. What is more likely is that however hard you tug the shaft remains firmly fixed in the axle tube. This is where the slide hammer comes to the rescue.
You can buy slide hammers, or if you are lucky like me can borrow one from a friend. If you are clever enough you can weld one together fairly quickly. For those of you who have no idea what I'm talking about, a slide hammer comprises a long rod of steel (say 18") onto which a heavy lump of metal with a hole drilled through is placed so that it can slide up and down the rod. At the top end a nut or something similar needs to be welded in place to stop the weight from falling off the rod. At the bottom end, a plate of metal, cut with 4 slots that match up with the wheel nut studs, needs welding in place. When finished, you should be able to slide the weight up and down the rod freely, and the bottom plate can be used to attach the hammer to the end of the shaft using the car wheel nuts.
With the hammer tightly fixed to the half shaft, you can start throwing the weight along the rod, letting it crash into the top end nut. As you do this, the shock will slowly pull the half shaft out of the axle. It will come out quite easily using this tool.
With the half shaft out of the car, clean all the differential oil off it and remember to take great care not to damage the splined end of the shaft. At the bottom of the shaft you will see the wheel bearing which is held in place by a steel collar. Both these items have been pressed on to the shaft.
Before we go any further, if you stop and think, you will realise that it is only this retaining ring that stops the half shaft from sliding right off the car -
Changing the bearing is a two-
To fit the new bearing you will need to turn the half shaft upside down in the press. Make sure the retainer plate is still on the shaft, otherwise there will be lots of tears afterwards! Wipe the shaft down and slide the bearing on, oil seal facing the splined end. If you do not know which way round this is, the bearing has a flat plastic side and a more recessed rubbery side. The flat plastic side should face the wheel studs.
Pressing the new bearing on is much less stressful. Make sure that the shaft is straight before pressing. Keep going until you feel the bearing push tight against the steel shoulder at the base of the shaft. Now you can do the same with the retaining ring that will stretch as you press it on. Again, this needs to be tight up against the bearing. There you have it, all ready for fitting back in the axle!
To refit the half shaft, first wipe away all traces of oil from where the bearing sits, and slowly slide the shaft into the axle. Before pushing the shaft home, I recommend that you smear the outer surface of the bearing with blue gasket sealant and then push it hard into its recess. You may have to twist it a bit to get the splined end located. With the shaft re-
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