Problems Removing A10 Primary Chaincase Inner

[trevinoz]

It is common practice to leave the front section attached to the inner case off. I feel it will protect the inner case if the chain is thrown.
The FERC is simple to remove, just take out all bolts. two in the rear section and two each in the top and bottom.
Remove the chain and juggle the inner case off. It is a bit fiddly getting it around the sprocket but it is obviously possible or or wouldn't be there.
Replacing the chain is not easy. I feed a piece of approx 1.6mm steel wire around inside the enclosure and connect the chain to it and pull it through.
The gearbox nuts are 25/32" AF, one of BSA's oddities. Same size as the oil pump worm and lock nut.
Iain, you are correct in your assumptions. The front section bolts are long and go right through and the top and bottom sections of the chainguard do slide. Yes you do fit the chain with the chainguard off.
Trev.

[tombeau]

I take it that you've tried getting at those nuts from underneath the bike and from where the back wheel used to be?
I would be starting to think about taking the heads off those bolts with a dremel. If it really is that awkward BSA must have issued a service sheet about it.
Iain

[trevinoz]

Adrian,
            What you have is stock standard BSA parts, although the chainguard is optional.
Even if you had the one piece top run chainguard, you would still have the front section which is giving you so much grief.
The inner will come off with the section bolted to it, it has to.
Trev.

[brackenfel]

Yippeeeee, success, the thing is off!!

Thanks to Trev & all who have posted & offered encouragement..
For future reference (and any other FERC owners!) you don't have to remove the FERC first, it comes off with the primary case. You do however have to take the chain off and move the gearbox well forward...

So, now all I need is some more time, some gaskets etc & some luck getting it all back together (the chain is going to have to be fitted after the cases!!)

One final question, on this thread at least . What is the little brass pipe hanging out the back of the crankcase (see photo below) I have a feeling it has maybe been contributing to the oil escaping. I intend to connect a pipe of some sort to it & find out :-



Many thanks again for all your help & encouragement. I hope as I get more familiar with the A10 I can help others along the way..

Cheers,
Adrian

[bsa- bill]

Hi Adrian
The brass tube is an mod fitted by a previous owner , it is pushed into the end of the breather circuit and would probably have a flexible pipe connected to it possibly routed to feed oil/oil vapour onto the rear chain .
I did this on my first A10 ( which was also 1961 - does it by any chance a welded bit at the bottom of the timing cover  )

All the best - Bill

[Hubie]

Does anyone have a photo of the sliding seal?  I need to make up one as it appears part of mine is missing.

Thanks,

Hubie

[flashblack]

Hi Hubie, and welcome, here`s a pic of one on e-bay:
  http://cgi.ebay.co.uk/NEW-CLUTCH-SLIDING-PLATE-BSA-A-B-MODELS-A7-A10-B31-B33_W0QQitemZ360220271324QQc

regards rich

[Hubie]

Thanks for that Rich, I have the same on my bike, but there is a decent gap between the gearbox shaft  and the plate.  There is obviously some kind of washer/seal  or o ring that goes in there.  I am going to get some rubber sheeting and make up a seal to go behind the plate and in between the felt washer that is on the bike now to stop the ATF getting flung out of the primary.

It is either that or use chain lube instead.

Cheers,

Hubie.

[flashblack]

Just a thought, is it definitely  coming out of there, or is it oil mist being blown out of the engine breather ?
  Rich

[Hubie]

Definately coming out of there, nice red ATF!

Cheers

Hubie

[trevinoz]

Hubie,
             The clutch centre hub should be a close fit to the sliding plate with almost no gap around it.
What clutch are you running?
If a six spring, there should be scrolled oil slinger pressed onto the gearbox end of the hub.
If a four spring, the slinger is machined into the hub.
Trev.

[brackenfel]

Hi Bill,
Thanks for the advice about the breather mod.. Mine has engine / frame numbers from '61 , registered May '62 so I'm afraid it's probably a different one.
Got to get some gaskets, bolts (the long ones for the chaincase / FERC front are bent!!) & start putting it all back together..

Adrian

[Hubie]

It appears then that the oil slinger is missing.  The bike is running a RGS clutch (4 spring) with the clutch hup doubling as the bearing surface for the rollers on the clutch basket.  If I can't find something to do the job, I will make something.

Cheers]

Hubie.

[orabanda]

Contact Colin Tie (Perth WA); he makes and  / or modifies the backing plate and installs a seaql. It works much better.

9295 6875





Richard

[orabanda]

This is how I added a pipe tp the breather hole, to prevent the crankcase oil / air making a mess at the rear of the crankcase.



Mind you, the original arrangement ensures that the chain is always lubricated!
Richard

[Hubie]

Thanks a million for that mate,

Now I know exactly what I need to get done.  Those picutres are a big help.

Cheers

Hubie.

[bsa- bill]

I recall a trader (sorry can't remember who - was on Ebay) stating that the hub adaptor he was selling had the scroll the correct way unlike some others on the market.
So there are hub adaptors out there that are going to scroll oil out instead of in.

All the best - Bill

[brackenfel]

Hi Richard,
Very neat, many thanks for the pics...

Adrian

[trevinoz]

Hubie,
              The scrolled slinger should be a machined part of the hub, unlike the six spring type which has a pressed on part.

Richard,
              I like the seal but I guess the hub has to be machined off to accommodate it. Correct?
  Trev.
           

[orabanda]

Trev,
Correct!