Author Topic: 1946-48 gearbox....again!  (Read 295 times)

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Pete C

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1946-48 gearbox....again!
« on: 09 April, 2021, 10:37:52 »
How much oil should go in a 1946-48 version of the gearbox (1948 B33) ?

I'm filling via the filler cap hole and can only get about 250mls in before it reaches the level of the hole. This doesn't seem to be enough, or is it? I can't find much on these boxes but I didn't expect it to be less than the usual pint.

I even used warmed oil to get it to flow into the inner case quicker!

cheers
Pete

Bess

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Re: 1946-48 gearbox....again!
« Reply #1 on: 09 April, 2021, 13:57:56 »
Hi,
     The manual and service sheet 701 states 1 pint.

Best wishes...

Jim S

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Re: 1946-48 gearbox....again!
« Reply #2 on: 09 April, 2021, 14:39:19 »
If you put 1 pint in, you will find significant oil splotches under your bike unless you have installed a sealed bearing on the output shaft. Yes, the B33 manuals say add one pint but review this previous post.
https://www.bsaownersclub.co.uk/bsaoc_forum/index.php?topic=8337.msg42035#msg42035
I run my 1949 B33 with 400ml in the gearbox.

idie

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Re: 1946-48 gearbox....again!
« Reply #3 on: 09 April, 2021, 18:04:59 »
My 1949 M33 is ok until I leave it on the side stand, then the pool of oil starts.

Pete C

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Re: 1946-48 gearbox....again!
« Reply #4 on: 09 April, 2021, 19:05:43 »
looks like I just need to fill it until it reaches the filler hole level.
The manuals all state a pint, so 570ml (even a US pint is 470ml), which is never going to fit in.
I have stripped all my gearboxes and fitted sealed bearings to try and keep the garage floor clean. Now just need to leak pproof the primary and crankcase....

Jim S

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Re: 1946-48 gearbox....again!
« Reply #5 on: 09 April, 2021, 22:35:54 »
Did you put a sealed bearing on the right side of the gearbox main shaft also? If yes, maybe that sealed bearing is preventing oil from migrating into the main section of the gearbox. You may be only filling the gear change and kick start ratchet area!

Pete C

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Re: 1946-48 gearbox....again!
« Reply #6 on: 10 April, 2021, 07:46:35 »
No, sealed bearing only on the sleeve gear end. There are enough galleries in the inner case to let oil into the main case so the bearing on the gear change end shouldn't be a problem anyway.
The kickstart mechanism being inside the main case instead of with the gearchage mechanism is another reason why I stripped out the gearbox last night and will be replacing it with a modified later box and Triumph clutch. Not standard but more pleaseant to ride.
I completely reconditioned the 1946-48 box a couple of years ago with the best parts from 2 boxes, plus parts from as far afield as australia, and it works perfectly on the bench. But in combination with the 6 spring clutch I just can't properly enjoy riding it.
now if only it would stop snowing!!