Problems Removing A10 Primary Chaincase Inner

[tombeau]

Hi,

It should be  possible to remove the splined shaft that the footrest attaches to with the chaincase still in place.It is a tube with a cam shaped disc on the bottom which has a peg on it, this locates in a hole and stops the tube from spinning around.
You should be able to loosen it from the frame quite easily, and with a bit of wiggling it will come out.

When I take the chaincase off my bike, I don't seperate the footrest from that shaft, I just wiggle the lot out in one go.

I think that you have to rotate the thing so that the tube is pointing downwards for it to clear everything, but to be honest I don't remember, play around it does come out of the gap between frame and chaincase.

Admittedly I dont have a fully enclosed chainguard (or any chainguard for that matter) but I wouldnt think that it would affect this.

Cheers,
Iain

[trevinoz]

Adrian,
                As pointed out, you have to remove the rear chain to get the inner case off.
It takes a bit of juggling around the gearbox sprocket but will come off. there is no point in removing the sliding plate in situ.
The footpeg and splined shaft should be able to be pulled out and rotated as has already been stated previously.
I always put a gasket either side of the front steel spacer, usually you have to make your own.
If you are successful in removing the inner, make sure the footrest assembly is loosely in place before reassembling.
Perseverance will pay off.
Trev.

[brackenfel]

Thanks to Richard, Iain & Trev...

I've been encouraged to persevere, for a while at least!
The gearbox was filled up to the level & so far looks ok.. Yes I do have the FERC diagram & it's a real monster in the flesh!!
I tried a bit of lateral thinking (probably not good at my age!) & moved the gearbox forward. Despite having dozens I couldn't find a spanner to fit the gearbox nuts so (may I be forgiven!) used a 20mm which was a snug fit! They were VERY tight !
I got the footrest mounting casting out & now know why getting the long spindle out initially was such a hassle - the splined tube is bent!!
Still can't get the damn casing off though.. The (enormous) sheet metal part of the fully enclosed chain is still an obstacle.
Now, I've looked in Haynes, the BSA owner booklet, Service Sheets, on the web, without luck.. Just how bad is rear chain removal as no-one seems willing to describe it!! More to the point, given the size of the front part of the FERC unit how the h*ll do you get the rear chain back on again??

I am getting there, the bike looks more naked by the day, the pile of bits on the garage floor gets ever bigger and the list of things to buy longer.. Oh dear, this is starting to look like another project....

Thanks.
Adrian

[tombeau]

I have never looked closely at one of the se FERCs before, but looking at the drawing:

The back curve is held on by 2 bolts and captive nuts.
Remove that, spin the wheel until you can see the split pin, get that off and whip the chain off.

IT LOOKS LIKE the upper and lower sections are only held on by 2 bolts (and captive nuts ) per section. With those bolts off I would PRESUME you could drop out the bottom section and lift and wriggle out the top section.

I would GUESS that those sections are not bolted to the section that encloses the gearbox sprocket, as those sections of the chainguard have to rise and fall with the swinging arm,  so they probably just slide loosely over the gearbox sprocket section.
Somebody here must know if this is the case.

It looks like the section that encloses the gearbox sprocket is attached by a bolt to the threaded hole that is on the top of the primary chaincase, There seem also to be 2 holes either side of the sprocket hole.

Are the bolts for the sliding plate (on the inner chaincase) considerably longer on models with FERCs and do they go all the way through to the other side of the gearbox sprocket section of the FERC ?
This might have been explained already, I just havent read the post thoroughly enough

I would also GUESS that when refitting the chain, you do it with top and bottom sections off the bike and then refit them once the chain is on.

Now we know why this is such a rare part...a young guy with work tomorrow and a chisel!

[brackenfel]

Hi Tombeau,
I've got the 3 easy bits off (had to remove the wheel to get the top section back out of the way.. The problem is the front section. The bolts from within the primary case by the slider are longer than the standard ones. Sadly the nuts are not (as far as I can see & from the parts lists) captive & getting around the back to hold them is impossible...

I can almost get the primary inner out with the front section still attached but not quite.. I need to be sure I can get the chain back on the front sprocket before I even consdier removing it.. It's nothing like a standard  case, it wraps right around the sprocket & extends back over the footrest shaft by at least 1" & is the same length top and bottom...

I too see why these are rare.. The bent  splined footrest holder has 2 chain grooves under the powder coat  so once upon a time either it was from another bike or someone fitted this damn FERC afterwards in place of a standard one..

Adrian

[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