Help requested. OLD Bosch SB 400-2 dismantling/service advice...

[SavageGardener]

I understand your confusion, I re-read the post and I'm really bad at nomenclature, I'm sorry.

I've finally found a drawing of the parts, well, the caption isn't of my particular model but everything looks exactly the same, and I can see the missing bits. If you look at it my garbled rambling incoherencies might make more sense.

The missing part - and I can find no trace of it - is a sintered metal bushing with, possibly two lubricating felt pieces either side. It's item number 11, There's no missing bearing, the design is a lot less complicated and elegant than one might think.

Fortunately the website I got the diagram from says the part(s) are available. Unfortunately it appears to be an American site so the shipping alone may be prohibitively expensive. I don't have the actual Bosch part munbers either, which will make sourcing the part(s) elsewhere avery difficult.

 

[AES]

OK, thanks. The "picture" is much clearer now!!!! And thanks for not being offended about my comments either.

That rear bearing is properly called a plain bearing - as you say, most probably sintered, and most probably phosphor bronze (because that material is slightly porous, and when new it was soaked in oil before assembly). And that's what the felt pads are for too.

OK, so where has that rear bearing gone then?

Like in my previous description, the overall dimensions are still, VERY roughly, about one inch in diameter and about half an inch "thick" (long). So it can't have escaped the 2 casing halves before you split them (none of the existing air, etc, holes are big enough, and there's no sign of a new hole that shouldn't be there until the "escaping" bearing tore it's way out)!

And though I'm definitely NOT an expert, I honestly cannot for see any forces great enough to have caused that bearing to have disintegrated into small enough pieces to have escaped through any of the existing air, etc, holes either.

Ergo, that rear bearing MUST be there somewhere on your shop floor, because it can only have escaped when you split the casing halves. It must be more or less intact (though doubtless badly damaged) and though probably discoloured now, it was most probably originally a sort of dull coppery/brass colour.

HOWEVER, I see from the diagram that the OEM is a company called Scintilla AG, in a place called Solothun, Switzerland. You may have noticed from my profile that I live in Switzerland and it just so happens that Solothun is only about 20 mins drive from my home. I THINK (not sure) that Scintilla still exists, so if you like, it's easy for me to contact them on your behalf to see if they have that bearing (+ felt pads?) in stock or orderable. Before I do that however I think there may be more paperwork than you've posted here, so I'd like scanned copies of the lot please. There may be numbering or German wording which will help if I contact them.

AND you should also note that postage here is not only VERY high cost, I would regard it as extortionate - to the extent that when we have parcels to post overseas we usually cross the border into Germany to do so (about 20 mins in the opposite direction to Solothun). Can't do that these days though (Covid restrictions) and likely to get even worse on the German side (worsening "numbers", with even stricte rules, likely to come into force this week).

So the long and short is that IF I can get that bearing for you, at a guess I'd say it would cost at least the same "prohibitive" amount that you'd pay for posting from the USA (logic and distance does NOT come into it where Swiss Post charges are concerned)! And on top of that, in both cases, you'll have to pay Import Duty (perhaps), Customs clearance charge (perhaps) and certainly UK VAT.

So it's up to you mate. Think it over - but I'm (almost) prepared to bet my shirt that that rear bearing (plain bush, whatever you want to call it) IS there somewhere with you, and it COULD just be re-usable!

But as said in the previous post, forget "spacers" or whatever, that drill will NOT run without it's rear bearing, sorry.

HTH