The BSA A7-A10 Forum

Technical => Clutch, Primary, Gearbox => Topic started by: Stretch on 31.01. 2016 09:17

Title: Gear box oil
Post by: Stretch on 31.01. 2016 09:17
Hello

I'm very new to the bsa world so please bare with me.

I'm in need of some  advise, I have a 1949 A10 that I have just picked up, after a lot of time stripping the tank and carb and cleaning the conjealed dried fuel from both and finally getting the bike to run  *smile*

Can any one tell me how to check the gearbox oil level?
Also the primary chain oil level?


Thanks guys
Title: Re: Gear box oil
Post by: terryg on 31.01. 2016 09:47
At http://www.a7a10.net/forum/index.php?topic=454.0 (http://www.a7a10.net/forum/index.php?topic=454.0) you'll find a link to a handbook for 47-50 models.

Fig 4 shows the primary chaincase level checking screw.

The handbook is less help on gearbox level checking, mentioning only that there is a level checking plug (hex head bolt). It is most likely on the rear right hand side of the box, about half way up.
Mine are all later machines but no doubt someone will chime in with some more definite advice.
Title: Re: Gear box oil
Post by: Stretch on 31.01. 2016 10:18
Thanks Terry that's really helpful for the manual, I just don't want to ride the bike before knowing how much oil I need in both
Title: Re: Gear box oil
Post by: terryg on 31.01. 2016 10:30
If you're not used to early BSAs it is worth checking the forum threads on wet-sumping.  These bikes have gear type oil pumps that (when worn) allow oil to drain from the tank to the sump when left standing for long periods.  If you start the bike with too much oil in the sump it can lead to problems.

New owners often check the oil level in the tank, see it is low and top up accordingly - only for the bike to pump the oil that had drained into the sump all over the floor and in the process usually oil up the plugs.
If the previous owner fitted a sump plate with a drain screw you're lucky.

This is not something to worry about over much but it is something to be aware of!

In any event, on a bike new to me I would change the engine oil, amongst other things, as a first precautionary action.
Title: Re: Gear box oil
Post by: duTch on 31.01. 2016 12:34

 Hiya Stretch, welcome along.
   What Terry says, and if(when) you change the oil, you'll have to drop the sump cover anyway and under normal circumstance should have (only) about 150 ml/ 6oz's of oil to catch. If it's been sitting for a while you may have more.

 Gearbox takes about 400ml and you should be able to see the level through the end cover, which you'll need to remove to add any anyway. The correct level is roughly about the top of the layshaft, so if you can see any at all you're in the ballpark.

 Happy riding
Title: Re: Gear box oil
Post by: bikerbob on 31.01. 2016 14:05
If you have just bought the bike and do not know the history. I would drain all oils and fill with new. I have never owned an early A10 only swing arm model. But according to Roy Bacon's book on the twins that particular model should have 284cc or 0.5 pint in the primary and 568cc or 1pint in the gearbox. I never go off level screws or bolts but much prefer to measure the exact amount of oil out that way you know you have the correct amount of oil in the bike. On all my BSA bikes that I have or owned I use 20w fork oil in the primary and EP80/90 in the gearbox also classic 20w/50 in the engine with an inline oil filter fitted, no doubt others will have different ideas but I have had BSA bikes for over 20 years now without any oil related problems apart from the aforementioned wet sumping. Not all bikes wet sump.  I have a 1956 A7 that either has to be run every week or the oil drained from the sump and an A65 that can stand all winter without wet sumping. This wet sumping is particular to each bike they are not all the same, as I said the A7 needs attention once a week but my previous A10 did wet sump but could go a month with out problems then after that if you started it up you would end up with oil on the garage floor.
Title: Re: Gear box oil
Post by: RichardL on 31.01. 2016 14:58
Stretch,

Welcome to the forum. On a bike that was just acquired, I think I'd pull the sump plate in any case, not just drain the wet-sumped oil via the plug, if there is one. There is a lot to learn from this. You can see if what comes out includes any metal bits, unexpected fluids (like gasoline or water) and if the screen and pickup tube are in good shape. If there's trouble, you'll be glad you found it now, if not, you'll be glad for that little piece of mind.

Richard L.
Title: Re: Gear box oil
Post by: muskrat on 31.01. 2016 18:58
G'day Stretch.
Level plug arrow'd.
Cheers
Title: Re: Gear box oil
Post by: Stretch on 31.01. 2016 21:24
Wow that's really helpful guys thank you, really appreciated
Title: Re: Gear box oil
Post by: cyclobutch on 01.02. 2016 15:48
Do we need to be talking about certain types of modern gearbox oils melting all the bushes at this point?
Title: Re: Gear box oil
Post by: Stretch on 01.02. 2016 20:02
Let's leave it for a minute I'm struggling to take this all in for now  *problem*   *eek*
Title: Re: Gear box oil
Post by: BSA_54A10 on 01.02. 2016 22:08
Do we need to be talking about certain types of modern gearbox oils melting all the bushes at this point?

Only truck oils still contain sulphur now days and I doubt he wants to run 110 in his box.
Most modern boxes have brass syncro cones so all modern gearbox oils are safe.
Title: Re: Gear box oil
Post by: Tomcat on 02.02. 2016 07:01
Welcome aboard Stretch, soon you will be an expert BSA mechanic!  The pic in your signature shows a 1947 A7 (XA7) a very rare bike indeed. But you say you have a 1949 A10 (ZA10 engine & ZA7S frame) ??? Enquiring minds need to know!  BTW, I also recommend to change all oils and drain sump plate. I run 20W/50 in the engine, ATF in the primary and 85/140 in the gearbox.
Cheers Tomcat
Title: Re: Gear box oil
Post by: muskrat on 02.02. 2016 08:14
Gee Tomcat I wasn't going to mention that!
Stretch, what are the frame & engine #s? Engine looks like a long stroke A7. Frames with an S in the prefix means sprung (plunger) frame.
Trying not to confuse you too early. *smile*. We're not really bean counters here.
Cheers
Title: Re: Gear box oil
Post by: Klaus on 02.02. 2016 09:12
Hi Stretch,

nice bike indeed and a wellcome also from the german side.


. We're not really bean counters here.
Cheers

but we all count rivets *whistle*

cheers Klaus
Title: Re: Gear box oil
Post by: duTch on 02.02. 2016 09:36

 And in addition to the above details which I omitted to mention for reasons of obvious, the speedo-in-tank was I believe only on the '46/'47 year.... *????*

 Was in a mission, so didn't look too close before.

 On the gearbox Oil thing, I' don't go too much on the level screws either,because if I do it frikkin' leaks...I know the Haynes is not well regarded, but it suggests 398cc/ml in the g-box, I said 400ml from the top of my minimal braincells, and it still overflows *conf*