Hi, My late father in law left me one of his motorcycles in his Will, I've had it several years but due to work commitments etc all i have done with it is keep it clean and occasionally start it.
The time has come now where i have time (retired) to ride it but before i do i need help with the basic service( I'm totally new to old British bikes), he did leave several service books but these are high level stuff for stripping and building the engine etc.
Having done a small amount of research the bike is a 1967 ex WD B40 (engine numbers are correct) that he has been changed to trial trim but is not a genuine trial machine from the factory, any help here in identifying parts would be greatly appreciated.
He has added Boyer electrics, modern oil filter and a trials petrol tank plus exhaust the frame looks right for a WD model and he registered the bike for use on the road where he took it to shows and meetings.
Anyway, I'm doing oil changes but i need help in the fact that there is no oil filler plug for the clutch side, like the early models up to 1965.
Question 1, did the WD change the design of the crank cases such that the clutch side lubricated from the engine oil, if not where do i fill from and how do i know the level?
Question 2, which bolt is the oil level on the primary side crank case?
I am not even going to ask the question which oil i should use as i have seen the hundreds of comments on the forum regarding this topic :) :)
I need to work out how to resize the photographs, i will post some once i have worked it out.
The parts book for the B40WD can be found via this link:
https://www.bsaunitsingles.com/Archives/Spares/BSA%2022019%201967-1973%20BSA%20B40%20MK1%20x.pdf
The workshop manual can be found via this link:
https://www.bsaunitsingles.com/Archives/Owners_Manuals/B40%20AWD%20Workshop%20Manual%201967%2000-4113%20x.pdf
From this you can see the chaincase drain screw is the screw closest to the lower engine bolt and the level screw is the second one to the right of it. Oil is replenished via the upper inspection cap.
It's a nice looking bike and has the benefit over a standard 350 cc B40 in using the later so-called welded duplex frame used by the B44 that is a lot stronger than the earlier swan neck frame used by the B40. The standard B40WD as used by the army is difficult to use on a normal road because the gear box ratios are very low especially in gears 1-3. However, for trials use, they will be fine.
Thank you for the info, i have downloaded to workshop manual and it shows a level plug and drain plug on the RH gearbox casing just behind the gear lever and a drain plug lower down, my engine has neither, can the oil level be filled through the inspection plate and perhaps one of the casing bolts is a drain similar to the primary side?
Hopefully better photographs
Quote from: straff52 on 30 May, 2023, 12:05
Thank you for the info, i have downloaded to workshop manual and it shows a level plug and drain plug on the RH gearbox casing just behind the gear lever and a drain plug lower down, my engine has neither, can the oil level be filled through the inspection plate and perhaps one of the casing bolts is a drain similar to the primary side?
It sounds as though you have a standard B40 outer timing cover fitted. On a standard B40, you have to fill the gearbox via the hex plug in the top of the crankcase on the RHS behind the cylinder. Whether standard or a B40WD, there must be a drain plug underneath the gear box. Where you might have a slight problem is that the standard B40 drain plug has a tube fitted to act as a level indicator. If you do not have one fitted, you will just have to add the correct amount of gearbox oil and not rely on using a level indicator.
I have located some useful information in my late farther in laws documents, it is an Ex war department parts list and diagrams ( i believe this is also available in the BSAOC library, my membership came yesterday), anyway I digress.
From the exploded views and parts list I have located the filler plug and the gearbox drain plug, the filler plug is what i thought was a breather for the crank case ::) the drain plug on the diagram is just a drain plug there is no level tube on it as per the earlier models, i therefore have no idea how the military used to check gearbox oil levels!!! Note the WD diagram shows a plug just behind the gear lever on the outer gearbox casing which i don't have (as your previous post i may well have an earlier outer casing).
Is this plug on the outer casing used to check gearbox oil levels on earlier models?
I'm considering purchasing an earlier drain plug with oil level tube as this will solve that problem as the G/B oil quantities are the same one i believe, a bit more reading required :).
You obviously have a standard B40 outer timing cover (the engine RH cover), whereas, the military version had the plug behind the kickstart shaft that was used both as a filler plug and a level plug. In other words, they refilled the gearbox via this hole until oil just started to pour back out. I think the reason for this timing cover plug was that using the standard filler tube connected to the drain plug was just too fiddly for the robust military way of doing things.