Dropping the whole thing in boiling water for a while to get everything really evenly heated then shaking the steel part out has worked for me.

If you think it might want little more effort make an expanding handle style thing to grab inside the steel. I have a section of Rawlstuds (expanding concrete anchors) about the place for this sort of thing which I use with a simple slit alloy drum made a nice fit in the part to be removed. The Rawlstud expands the alloy drum to grip the part.

Clive

Hello Roger

This is a very common situation amongst Austin Seven restorers (my own enthusiasm).

As Michael says a picture of the part might help, but as Clive intimates, heat is the one essential ingredient.

Depending upon what you are trying to do and its structure (which is why a photo might help) you may be able to make an extractor that will pull or push the bearing out. But even then, with old or fragile aluminium you need to heat things up. This, for example, is how one can remove Austin Seven main bearings from the aluminium crankcase.

Alternatively, if you can access the bearing with a brass drift – i.e. if it is not against a flange or lip – you may be able to knock it out. But again, heat is essential. Don't bash it cold. Old-fashioned brass stair rod may be suitable for the drift.

Try to heat the part to around 80°C and aim for generalized heat not local. A domestic oven is ideal for the purpose. In the Austin Seven context their steel hubs will give up their steel bearings quite readily when heated and you will probably be surprised how aluminum, once expanded by heat, will let go a steel bearing.

Good luck, just don't bash it cold!

Martyn

If the steel housing is no longer required, and it is intended to come out – get a bit of scrap steel that will fit inside the sleeve and stick weld ( or MIG ) steel to housing. This shrinks the housing and heats the ally, and provides something to hit or pull.

I would suggest that on something so small, it would have been cast in. can you not bore it out and make a press in end,then pin it in a couple of places to secure it?

This looks to me like the end casing of a magneto. If so, the steel bearing 'housing' may well be the outer race of the bearing itself. It will have a groove where the balls run, and there are pullers which expand into this groove so that the two can be separated. One way to do this without a 'proper' puller is to re-fit the ring of balls in its cage, and push a gently tapered steel bar into the hole (from below in your picture). This will force the balls into the groove and should give enough purchase to tap the outer race out. Don't go mad, though, as you can split the race and destroy the housing if you go too far. Old light alloy can be very much weaker than when it was made, after 100 years …

Alternatively it should be possible to make a puller rather like a 3 or 4 jaw chuck to fit snugly into the bearing, and with a sharp ridge around the extreme edge of the jaws which will locate behind the radius on the inside (lower as shown) edge of the bearing. There is not much room there, so it needs careful making, but you can be sure that there really is a radius in there. The photo is too blurred to show this.

Hope this helps

Cheers, Tim

I've re-built more than one mag in wet fields etc. I'm still assuming that the bit to be removed is the small dia. part in the middle, if so then welding a bit of steel in is the easiest way, or any of the heat and tap methods. If it is in good condition why remove it ?

On later magnetos the outer races of the bearings were insulated from the casing with dense insulating paper sleeves to avoid re-circulating earth currents being passed through the bearings and causing arc erosion. It may well be the case that this magneto has the same interface, in which case the differential heating method will not work – the paper grips both surfaces too well. Also, too high a heat and the insulator gets destroyed! I've sent you a personal message.

Edited By Swarf Maker on 05/02/2016 14:43:54

Edited By Swarf Maker on 05/02/2016 14:44:52

Try heating up in the oven, appox 200C ,like Colin suggests, and then slap it down firmly on the bread board,so the housing drops out.Good luck.Another way would be to drill a couple of small holes through the casing to the bearing housing and try punching or pressing out,but again using heat.Hope this helps

Not sure where you are based but I use a good and helpful aluminium foundry up here in the West Midlands. It is possible to "Wax " the original component to allow for some of the contraction. I would still as suggested machine from solid in a good spec aluminium though.