Problems Removing A10 Primary Chaincase Inner

[brackenfel]

Dear All,
I am new to this forum but have read quite  a number of posts so far.. I'm also new to BSAs (but not old bikes - have Velocette, Laverda, Matchless in bits etc etc ) having recently decided to sell my little VFR400 and buy a 1961 A10 as a regular ride...
That was the plan......  However.....
Although I rode the bike home & around a bit once the MOT haad expired I thought I'd "just check a few things over"!! Now there are bits of it everywhere.
Gear change wasn't great so I tackled the clutch. 20 tooth engine sprocket which is a bit unusual, 4 Spring clutch which had been wound up far too tight (had to drill 2 of the spring retainers to get them to undo). I have discovered that previous owner had a thing about grease (see photos to prove!!) which probably explained this when the clutch slipped it got tightened up some more..

As the bike leaks oil a lot on the LHS I thought I'd get the primary inner off as well - this would also give me a chance to look at the gearbox sprocket (the bike is a bit "buzzy" in top gear).
Now the problem.. The bike is fitted with the full rear chain enclosure. This has resulted in a chain so slack it's a wonder it stayed in place as PO had fed copious amounts of grease thru the inspection hole but clearly hadn't adjusted it! So, the back bits have been loosened & pulled back..
I can't get the primary case off though as the front bit of the enclosed rear chaincase unit is bolted to it with nuts somewhere round the back. The splined bit that the LHS footrest is still in place as that won't come out due to the same bit of pressed tin!!

Has anyone found an easy way here??  I'm about to get the rear wheel out as well to see if I can see any more from the back but am conscious that if I don't stop soon this thing will never get back on the road & will become a major "project"..

All suggestions appreciated..

Thanks

Adrian

PS thansk for your patience - there will be more questions...

[Desburnett]

Hi,

With the clutch basket removed you should see the heads of the two retaining screws that secure the sliding seal cover plate and secure the front section of the rear chain guard. If you cant get a spanner on the nuts at the back drill out the two fixing screws, new ones are avaliable and are cheap.

Cheers, Des

[muskrat]

G'day Adrian,
                 Welcome to the group. So thats why they call old mechanics grease monkeys. i have never had an enclosed chain guard myself, but by the sound of it you should remove the wheel and guard just to clean out all the grease. You might then be able to get to the nuts. Failing that use Des's method but be careful as the bolts have a shoulder that sits against the inner primary cover. It would be a good idea to replace the gearbox sprocket and seal while your in there. You may be able to clean the grease off the clutch plates with petrol but I would throw in new friction plates, springs and chain. The 4 spring clutches are sweet when set up right.
Remember, there is no such thing as a silly question ( just silly answers ).
Cheers

[LJ.]

Hi Adrian! Welcome along to the forum...

Yea strewth! your right about the Previous owner liking grease! What a mess, a complete good clean out of all that muck is in dire need. That primary chain also will need to be tighter than what I see in the picture. Like Des says there are two very thin headed bolts (normal) behind the clutch wheel that you need to undo, you'll probably need a clutch hub puller too as its nigh impossible to remove with out damaging it, don't ask me how I know!

'Oil Leaks a lot' hmmm wonder where from if the primary was bunged full of grease! You need a thicker oil in the gearbox, I use straight 50. While the clutch is off and you investigate the 'buzzy' gear check the oil seal just near the gearbox sprocket.

There's likely to be some more adjustments to be made while getting to know the bike but in time it'll be a really nice reliable bike to ride.

cheers! LJ.

[rocket man]

hi adrian welcome to the forum looks like a grease monkeys been at that primary
should only have oil in it looks like your going to have a lot of fun with your a10
there a good ride and a great sound




dave

[BSA_54A10]

The usual reason for greasing the primary is either ignorance or oil leaks.
Check the bolt holes in the primary you will probably find they have all "pulled out" so will need a little counter sink to allow the outer case to sit flat on the sealing face.
Naturally new chains and sprocket are in order and I would go for a new sliding plate as well.
The new aftermarket ones have far better oil tightness that the old ones.
Pack out the space between the gearbox sprocket and the inner cover sliding place with felt washers
Glue a thick fine grain neoprene cork gasket on the sliding plate and that will just about end oil leaking from the primary.
You will have to make this gasket yourself and buy the material from an engineering supply store , not an auto parts shop , the latter only keep cheap stuff which is not worth the time spent cutting the gaskets. If you are within striking distance of a port then go to a marine engineering supply store which is where the stuff that "can not fail in service " is  stocked. Ditto of aero supply stores, but they have aero prices for the same materials that the marine shops stock at marine prices.

There is a vent on the primary case which doubles as a chain oiler. It has an under cut in the inner side so that gasses and some oil can escape which dribbles down onto the drive chain, don't block it off.

Clutch has all the same problems as any other Pommie dry clutch has so you should be familiar with those. 

[1660bob]

Hi Adrian, welcome to the forum.Good luck seems like you have plenty to be going on with for now!!!!-I couldn`t resist a chuckle at photo 1-the arc of a probing finger around the pri case filler cap- I can imagine your expression at withdrawal of said digit dripping with grease "WTF......" Sympathies, Mine certainly turned into a "project" (of biblical proportion) and my "quick once over" turned into a horror story....Still, I suspect many on this forum have been there, and eventually come through with a decently sorted bike to enjoy... I`m a long way off yet but i keep focussed on some of the piccies of finished bikes herein....great therapy and incentive.Incidentally-look out for the small spacer(may be washer(s))part No:42-4792 between frame and inner primary casing where it is bolted to at bottom rear end(pic 2)-easily missed in all that gloop!Best of Luck-Bob.

[LJ.]

Incidentally-look out for the small spacer(may be washer(s))part No:42-4792 between frame and inner primary casing where it is bolted to at bottom rear end

Indeed your right about that spacer Bob and there was a thread devoted to this spacer sometime ago, most here seemed to have made up their own spacer as I don't think there is one size suitable for all bikes. Likely there will be two or three millimetres difference and again that could be the difference to clutch operations and leakage. I was not aware though that it also has a part number so thanks for that.

[The General]

On my 62 Super Rocket the inner primary case can be removed with the front chain guard still attached.
You have to remove the rear chain and other pieces of the guard.
It makes it a lot easier to get to the two bolts of the front guard.

[brackenfel]

Dear All,
Many thanks for the replies received, much appreciated..
I do have some new plates & centre rollers & have added various other items now thanks to suggestions to my list for the Bristol Show or the Shepton VMCC jumble...
A mate lent me a puller to get the clutch centre out which was no trouble. The clutch basket is notched by the plates, I presume the usual filing can be used here? I'm afraid due to budgets I won't be replacing everything in sight at this stage, bit of a "make & mend" really.
Thanks for the warning about the frame space at the rear mounting, typically I don't think mine has one - another for the list!

I'll get the rear wheel out next as I want to replace the tyre anyway and go from there..
Bob was spot on with the area around the primary inspection plug - just what I thought when I did a bit of "digital" investigating!! Tell you one thing though, although the plates didn't enjoy it once you wipe the grease off it leaves things spotless!!

Just to prove it wasn't a one off I attach a couple of pics of the other side....


Thanks again for the warm welcome, I will be back to let you know how things go & probably with more questions..

All the best,

Adrian

[rocket man]

looks like the old owner loved grease must have had shares in it
id look in the crankcases next and oil tank are they full of grease also   

[LJ.]

Well... congrats to the previous owner regarding the amount of grease in the dynamo chain area as that is not a bad thing. Just that you need to be sure the cork gasket is good and the dynamo is pushed well up to it.

[BSA_54A10]

The dynamo chain is supposed to run in grease.
I put Duckhams chain grease in there which melts at running temperatures

[brackenfel]

Many thanks for the replies.. Point taken about the grease, I'll put some fresh in the dynamo chain area...

However on the other side I've had another look & have decided on the "blow it" (or words to that effect!) approach... I still can't shift the inner, the casting with a spline that the LHS footrest fits on is in the way & won't come out.. Looks like it was put in place & then the engine put in afterwards!.
I'm worried if I do get the 2 nuts off the back of the slider I'll never get them on again, ditto if I remove the rear chain?.

Using a mirror & inspection light I can see up into the gearbox area & have cleaned it up a bit. I'm now going to refill the gearbox & if it doesn't leak in the sprocket area I'm going to chuck the whole thing back together.
I want to try & squeeze a new gasket around the crank area at the front of the case but am abandoning looking at the gearbox sprocket. I started this 'cos of the oil leaks & poor gear selection, the bottom line is that I need the bike to ride & not another project (I have 2 others that have been waiting a long time already..)

A quick question...
This is a 1961 bike (reg'd in '62) and according to the Draganfly catalogue uses 2 gaskets behind the crank end of the primary chaincase, one for other models. Anyone know if this is 2 together or one either side of the steel plate?  In my spare bits that came with the bike is a gasket for the crank end that is quite thick ( a bit like me !) , about 1mm , can I use this place of 2 thinner ones ??

Looking at part lists the "spacer" used at the rear seems to vary with year too. As it fits behind the frame, I presume this spacer goes between the frame & case (again the catalogue doesn't make this clear, showing at the nut end). There doesn't naturally seem to be a gap, should I force issues to create one by inserting a thin spacer??

As usual any thought appreciated..

Cheers,
Adrian

[RichardL]

Many thanks for the replies.. Point taken about the grease, I'll put some fresh in the dynamo chain area...

But not as much and of a better grade, I trust.

However on the other side I've had another look & have decided on the "blow it" (or words to that effect!) approach... I still can't shift the inner, the casting with a spline that the LHS footrest fits on is in the way & won't come out.. Looks like it was put in place & then the engine put in afterwards!.
I'm worried if I do get the 2 nuts off the back of the slider I'll never get them on again, ditto if I remove the rear chain?.

Someday that footrest will have to come off, will doing it then be easier and more productive than doing it now? I suppose you already have this drawing of the chaincase, but, what the heck. http://www.a7a10.net/forum/index.php/topic,430.msg2163.html#msg2163

Using a mirror & inspection light I can see up into the gearbox area & have cleaned it up a bit. I'm now going to refill the gearbox & if it doesn't leak in the sprocket area I'm going to chuck the whole thing back together.

Using ATF or appropriate motor oil to the correct level according to the overflow indicator hole, I trust.

I want to try & squeeze a new gasket around the crank area at the front of the case but am abandoning looking at the gearbox sprocket. I started this 'cos of the oil leaks & poor gear selection, the bottom line is that I need the bike to ride & not another project (I have 2 others that have been waiting a long time already..)

A quick question...
This is a 1961 bike (reg'd in '62) and according to the Draganfly catalogue uses 2 gaskets behind the crank end of the primary chaincase, one for other models. Anyone know if this is 2 together or one either side of the steel plate?  In my spare bits that came with the bike is a gasket for the crank end that is quite thick ( a bit like me !) , about 1mm , can I use this place of 2 thinner ones ??

I don't have my parts book with me, but it sounds like you're seeing a gasket and a metal spacer. This would be a good place for others to jump in.

Looking at part lists the "spacer" used at the rear seems to vary with year too. As it fits behind the frame, I presume this spacer goes between the frame & case (again the catalogue doesn't make this clear, showing at the nut end). There doesn't naturally seem to be a gap, should I force issues to create one by inserting a thin spacer??

I think this would be a small gap if you are missing the thick spacer between the front of the case and the crankcase. I have wondered why there was need for this spacer (chaincase to crankcase) in the first place and the only thing I have thought of is that BSA discovered that the cushnut hit the outer cover without it and they preferred to make a spacer rather than retool the die for the outer cover.

As usual any thought appreciated..

Cheers,
Adrian

Regards,

Richard L.