How do I rebuild my generator?
Bearings, I simply clean all the old grease out of them, and repack them with Castrol LMM, Molybdenum Disulphide grease. The LMM grease is high temp grease with anti-seize properties used in sealed applications, like CV joints etc. I have found it quite OK in generator bushes, elect motor bushes, wiper motor gearboxes, drive shafts and so on. And it's a reasonable costing item
To rebuild your generator, pull it apart, they are super simple, with a brass bush on the end away from the pulley and a ball bearing on the pulley end. You will find that if the ball bearing has seized and probably that the pulley has sheered the woodruff key. Short of the whole thing going "pear shape" (and I really mean pear shape, or out of shape) there is nothing else in there that can seize the generator.
If the shaft with the woodruff key is still presentable, and hasn't been ripped apart, take the woodruff key out and try and take the end plate off the shaft. If the bearing is seized it will be a pain, probably if you know someone with a press, take it to them to get them to press it off. DO NOT TRY AND BELT THE SHAFT OUT OF THE BEARING/END PLATE with a hammer, nor even a brass drift. All you will do will be to successfully stuff the thread, and that's a drama in its self.
When you get the end plate off the shaft take the bearing out of the end plate, by knocking out the 3 rivets round the bearing housing. This will release the bearing from the end plate. You will find that the bearing is a common standard size available at any bearing supplier. When you buy a new bearing make sure you get a prepacked and sealed bearing, (they are as common as the "common cold", I just cannot remember the number). When you come to reassemble the end plate and the bearing, instead of trying to replace the rivets, just simply use some appropriate length (I think) 3/16" bolts to hold the cover plate on, and the bearing in. Make sure the head is on the inside and the nuts on the outside.
Whilst you have it apart get the commutator machined nice and flat and "square" before fitting new brushes. As Daniel said the brushes are still available and any good auto electrician should have them. When you install the brushes make sure you shape them to the new size of the commutator. This can be achieved by wrapping some 180 or 240 wet and dry paper round the commutator and turning it under the new brushes. Make sure the brushes are tensioned with the spring installed on them. You will then shape the new brushes to the shape of the commutator. Assembly is simply a reversal of the dismantling.
Failing all this, you can seek solace with your friendly local Auto Electrician!!!!!
Generally the Sheerline has a fairly common Lucas type generator, a C45P, fitted to heaps of different pommy vehicles. The main thing that changes is the pulley size and type of belt each uses.
Ken Gardiner - New South Wales, Australia