The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: philwhitelaw on 13.04. 2019 08:23
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Hello all,
I have a leaky chaincase on my 1961 A10 that wont go away and was wondering if anyone has tried to replace the oil with a low melting point grease. The dynamo chain is lubricated this way but the crankcase gets warm enough to melt the grease and pool at the bottom of the cavity. The rear of my primary chaincase stays quite cool so I imagine the grease would just initially fling itself off the clutch basket around the inside of the case and stay there, the result being a dry chain. Any thoughts?
Phil W.
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How much oil are you putting in the case?
Have you cleaned up the case mating surfaces?
Are you using Allen screws or slotted screws?
What sealants have you tried?
Please will you go to Introductions and tell us something about yourself and your motorbike history.
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Hello, IMO, the chain won't last long... or using chain lube regularly as you would on the drive chain could maybe work ?
Also, shock absorber and clutch are constructed to run in oilsplash conditions.
Best is to work on the source of any problem, not symptoms :O) So I'd look at how to fix the leak.
Those who have belt conversion may chime in.
The intro post is always appreciated :O)
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Worth considering that it might not be from the joint it could be leaking from the sliding plate where the clutch centre passes through or could be seeping from the gearbox mainshaft or could be blowing from the breather.
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An old trick was to put a spoonful of tallow in the case as well as the usual oil. Some riding mates of mine have said a spoonful of grease worked as well.
The grease is supposed to find the leaks and clog them up.
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T T.. A candle from the corner shop was the favourite on Matchless Tinny Primary Covers. Melt on the gas stove, pour it into the cleaned out case, slosh it a bit, leave to set. Then add the oil. Seemed to work....well enough to sell on. Very unusual to have a BSA that drips anything ......in my limited experience.
As to the problem in hand, Julian has covered sources of fake leaks. "They all do that Sir"
Reasonable inner and outer faces will seal easily with a good gasket and a thin smear of the dreaded silicone sealer, plus a check that there is nothing down the bolt holes, bottoming the bolts and preventing full clamping pressure on the gasket.
Swarfy.
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Very unusual to have a BSA that drips anything ......in my limited experience.
You're kidding, right? In my limited experience they're humorously known for leaking (set aside any lack of diligence on my part leading to the leaks on my own bike).
Reasonable inner and outer faces will seal easily with a good gasket and a thin smear of the dreaded silicone sealer,
...but nowhere where silicone meets engine oil, please. (That's why Swarfy said "dreaded.")
Richard L.
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Rich. Dead right. Silicone in the wrong place is certainly a no no. Keep well away from oilways. A smear is all you need. Bolt up loosely, let it cure overnight and finally tighten the cover down.
Yes, couldn't resist that little joke. Its almost the free added extra, all for the sake of wafer thin joint faces in critical areas. No wonder the Japanese cleaned up the market.
My 53 Plungy had no chance of the stand rusting away, when I got it. When I announced to my mates, way back, that I was getting a BSA, the response was that I was getting a "dripper."
Swarfy.
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This is an ongoing problem with our bikes that I am not aware of a guaranteed solution. In my own case I had a 1957 A10 swinging arm model for 16 years and I never had an oil leak from the primary case the garage floor was always oil drip free no matter how long the bike stood. I now have a 1956 A7 and I have had the primary side stripped a number times to try to cure an oil leak with only limited success, it only leaks a few drops after it has been out on a run never while just parked in the garage it can stand months with no leak but go for a run and sure enough I get a few drops of oil leaking. So now because I hate seeing oil on the garage floor I park the bike after a run on a sheet cardboard until such time as someone can come up with a guaranteed solution. The only difference between the 2 bikes is the A10 had a four spring clutch and the A7 has the original 6 spring clutch, but both bikes still relied on the sliding plate with the felt seal. Now I do think that it is important that the relationship between the sliding plate and the reverse scroll on the clutch sleeve is correct this is determined by the taper and I have found that using differnt clutch sleeves can alter the position of the scroll to the sliding plate. Also when ever I adjust the primary chain after setting the correct tension I always move the gearbox a touch so that the scroll is not touching the sliding plate.
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I think its your breather that makes your drip, I thought it was my primary until I got neck pains looking under there and wiping the inner case down . ps I went to the pub *beer* *countdown*
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Hello, IMO, the chain won't last long... or using chain lube regularly as you would on the drive chain could maybe work ?
Also, shock absorber and clutch are constructed to run in oilsplash conditions.
Best is to work on the source of any problem, not symptoms :O) So I'd look at how to fix the leak.
Those who have belt conversion may chime in.
I have a belt drive - so I'll chime in! Owned the bike for over 30 years and don't think the chaincase was ever totally oil tight in all that time, but how much it leaked depending upon how much time, care effort etc I put in to it. If it ever did stop leaking for a bit, I was always concerned that the oil had run out. To be honest, if you run a 60 year old bike, you aren't ever going to have it leak-free like a modern bike. As a long term owner I've always lived with a oil smears and light leaks, but fixed big leaks. I'm happy with that.
I eventually bought a belt drive as I prefer the technology of that to a diddy little chain in a leaking case - so no more oil drips. Also runs quieter and smoother as an added bonus. Expensive, but worth it, although I appreciate that that is probably not the solution to suit everybody!
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If all else fails, a bolted on homespun drip tray will catch the small drops, and annoy the purists, but Niagara Leaks should be easy to find and need fixing pronto. I go with the racer on this, if it's dripping, there is reassurance that there is still some oil left. Time to worry when the drips stop.
Swarfy.
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Phil - it's nearly 50 yrs since I put oil in a primary case - tell a lie, I put oil in my DOT'S case around 20 yrs ago - it all leaked out within a couple of weeks. I got fed up with primary case oil (more slipping clutches than leaks though) so for decades I've boiled the primary chain in grease (as I do with all my chains; putting oil or grease on the outside is a waste of time) and repeat every few thousand miles. As my bikes aren't 'daily drivers' that's several years.
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Hi All,
Deja vu all over again *roll* *roll*
A forum search will reveal lots of threads on how owners sorted their primary drive oil issues
My experiences are that the repro sliding plates are crap quality as are the felt seals
Alloy sliding plates are available with a proper oil seal,
A cork washer can replace the felt, but the thickness is critical
A gearbox sprocket nut with oil seal is well worthwhile
If the engine is a bit tired or the rotating breather cork is loose oil will be thrown out the breather and appear at the bottom of the primary
I made my own "seal" but a breather had to be added to the primary case as pressure built up in there
John
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Thanks for all your replies gents. I have smoothed off the mating surfaces with wet and dry on a surface table. There is 200cc of oil in the case. I use wellseal goo and allen bolts, the bottom row with rubber o rings under the heads. I dont think the fasteners are bottoming out on the threads. The leak seems to be coming from the chaincase to crankcase area at the front, its not from the breather as the engine oil is a different colour. I have stripped it down a couple of times but it still drips quite badly during a run. Its not a real problem as I only do short journeys and keep an eye on things. As long as I can see oil fling when the engine is running I'm happy, its just a bit embarrassing leaving an oily puddle whenever I park up anywhere. Next time I take the outer case off I will put a bead of setting sealant around the area behind the drive sprocket and see if that does the trick.
Phil.
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G'day Phil.
I've never had much luck using o rings under the screw heads. Tightening the screw squashes the o ring out of shape and impossible to get good torque on the screws. I found thick fiber washers work better.
Does yours have the drain/oil level bolt from under the outer cover?
Cheers
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Have you got the two gaskets between the case, spacer and crankcase?
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the front three 5/16 screws go into crankcase and get oil down the threads and sometimes between engine and primary inner where there's two gaskets and a steel spacer, they can be a swine to stop weeping unless you want to put oil resistant thread lock on . not something I would do , I used a small amount of ptfe and it cured mine, make sure the inner case is plumb and fastens correctly to the frame near the foot rest, sometimes it has to be spaced with a washer or suitable spacer
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Hi Phil,
Welcome to the Forum!
Fibre washers behind the drain and level screws will seal them perfectly; o-rings are "hit and miss".
Draganfly and other well known BSA suppliers will have them.
Richard
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Phil, As mentioned earlier, (Trev) if assembled correctly your engine should have a circular metal spacer, 42-7509, between the drive side case and the inner primary cover. Listed as a "Joint Washer". Use two gaskets, one each side of this circular spacer, bedded with your favourite jointing. A cereal packet makes good material for these homespun gaskets and should stop the drips.
The primary case should not need O rings under the bolt heads. The chain case gasket seals the mating faces of the the inner and outer cases, this obviously includes the entire area around the bolt holes. When the cover is pulled down nice and tight, oil is excluded from the bolt holes as the gasket settles and seals. O rings will just get squashed. The exception is on earlier models which have cutaways on the internal face of the primary cover casting for level and drain. These bolt positions each need a fibre washer to seal. Thanks "O".
The inner case should bolt to the frame at the rear mounting without being under any strain, as berger says, washers or a spacer sometimes needed here.
Swarfy.
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I don't like Allen screws in these cases because they can be overtightened and distort the case and also pull up the metal around the threaded holes. If you must use Allen screws only tighten them with a screwdriver with a hex bit.
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Those fibre washers must be a special item, as I can't find them anywhere and even when I ordered them specially from the dreaded DraganQueens, they sent me something totally wrong *rant*- and 'O' rings didn't work for me either- but maybe worth doing them between the joint faeces
I don't like Allen screws in these cases because they can be overtightened and distort the case and also pull up the metal around the threaded holes. If you must use Allen screws only tighten them with a screwdriver with a hex bit.
I understand that, but in the words of Dirty Harry, " a man needs to know his limitations"....an Allen key will do the job if one doesn't use a breaker bar *work*
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Those fibre washers must be a special item, as I can't find them anywhere
I got lucky. I found a box of assorted fibre washers in Aldi's. I've put fibre washers on all the primary case screws.
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Quote from: duTch on Today at 20:01:24
Those fibre washers must be a special item, as I can't find them anywhere
I got lucky. I found a box of assorted fibre washers in Aldi's. I've put fibre washers on all the primary case screws.
The trouble with assorted packs is having 95+% crap that there's never a use for....until 10 seconds after ditching the 95% *eek* *pull hair out* *pull hair out*
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The trouble with assorted packs is having 95+% crap that there's never a use for....until 10 seconds after ditching the 95% *eek* *pull hair out* *pull hair out*
Aldi stuff is cheap.
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G'day fellas.
I use the thickest 1/4" id fiber washers, put 6 on a screw with a nut, stick screw in the drill and grind the od to size.
Cheers.
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Hi All,
I read on another forum recently where someone resorted to welding up the inner ends of the tapped holes
on the inner primary case *eek* *eek*
Non setting gasket sealer on the threads (hylomar or DP300) works well for me
John
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...I read on another forum recently where someone resorted to welding up the inner ends of the tapped holes
on the inner primary case *eek* *eek*....
yep *eek*.....*conf2*
....I use the thickest 1/4" id fiber washers, put 6 on a screw with a nut, stick screw in the drill and grind the od to size....
I did that with a couple but that stuff is harder than it looks *work*
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I use allen screws with no washers and use a allen key to tighten. no leaks and use ATF *beer*