BSA Owners' Club Workshop Discussions

The BSA Workshop => Singles => Topic started by: Mike Farmer on 11 Jun, 2019, 10:02

Title: WM20 gearbox parts
Post by: Mike Farmer on 11 Jun, 2019, 10:02
 :) :)

Hi all

Just stripped my M20 gearbox and it is in a very sad state---Bearings, bushes, shims and oil seals dead in the water.

Is there any where that I can go and get all the bits off the shelf or is it a case of making them.

I know Draganfly has some of but not all the bits that I shall need.

Your assistance appreciated

Mike 8) 8) 8)
Title: Re: WM20 gearbox parts
Post by: chaz on 11 Jun, 2019, 18:41
presumably you have tried the Dutch site?
if you have the machinery make the bushes your self, Im in France at the moment but I do know there is a service bulletin with sizes of bushes on. knowing British parts stores and designers its possible that later bikes used the same bushing so see if you can draw one up and check against the list. ebay might have some listed, you could try BSA bush in search and some sellers list size s on listing.
there are some bushes currently out of stock for the B40 which Ive found under Triumph numbers.
someone specialist like MArk Cook PES https://www.ccm-britain.co.uk/?xhtml=xhtml/homepage/default.html&xsl=homepage.xsl or Steve Riley at Piston Broke in Bristol 0117 941 2300 can make, or our own Rupert Ratio is well known..
if making yourself allow for interference fit on outside dia and a reaming allowance on bore. a phosphor bronze or similar is ideal, brass can be used..
Title: Re: WM20 gearbox parts
Post by: Mike Farmer on 11 Jun, 2019, 19:25
 :) :)

Thanks Chaz.

As things sit at the moment all the bushes, despite my original thoughts, are actually sound. Bonus!!!

I've also been able to source all the bits bar two, (I'll post the part No's tomorrow). So from an arm length list I am hopefully in a fairly comfortable position.

Fingers crossed. Your input appreciated.

Mike 8) 8) 8)
Title: Re: WM20 gearbox parts
Post by: Mike Farmer on 12 Jun, 2019, 09:54
 :) :)

The parts that I need now are :- 24-4235 Main Shaft Washer
                                                66-3071 Main Shaft Collar.

Drawings, patterns or an old one of these items would be of significent assistance.

Mike 8) 8)

Title: Re: WM20 gearbox parts
Post by: chaz on 12 Jun, 2019, 21:03
http://www.wdbsa.nl/BSA%20M%20type%20gearbox.htm
useful source for sizes and descriptions.

http://www.russellmotors.co.uk/Classic%20bikes/Downloads/files/bsa.pdf these might have some
Title: Re: WM20 gearbox parts
Post by: Mike Farmer on 13 Jun, 2019, 09:36
 :) :)

Thanks Chaz.

Mike 8) 8) 8) 8)
Title: Re: WM20 gearbox parts
Post by: paulm on 16 Jun, 2019, 08:18
Russel Motors have most stuff available Genuine BSA
Title: Re: WM20 gearbox parts
Post by: Keith L on 16 Jun, 2019, 09:13
Here is another possible source I have used.

http://www.stuart-bray-motorcycles.co.uk/parts/other-ww2-bike-spares/

Keith L
Title: Re: WM20 gearbox parts
Post by: Mike Farmer on 16 Jun, 2019, 13:38
 :) :) :)

Greetings and thanks for all your input and advice

I think that I now have all the bits needed so that my friendly Mr Gearbox can start to reassemble tomorrow. ( Really don't have the experience to do it myself).

I shall let you know. Thanks agen

Mike 8) 8) 8)
Title: Re: WM20 gearbox parts
Post by: Mark Cook on 08 Sep, 2025, 13:13
Our web address has changed.  We make many parts for the early bikes.

https://pesltd.uk/?product=24-4235

Mark