The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: Daniel Toro (DT) on 14.08. 2009 00:10
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Sorry, but how I disassembly this part?
The screw on the left is very tight and if put some pressure, all the engine turns.
The other one is the same, I don´t have any idea how to keep this part locked.
In the Haynes manual is very simple, but there they disassembly all the engine. Yes, quite easy. kkk.
I bought the seal and hope is this the problem. When I take off the cover, was full of oil, 1 liter I think.
Thanks.
Regards.
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Select 4th gear and have someone put pressure on the rear brake pedal to hold the assembly.
The front nut may have to be loosened with a drift and hammer.
The clutch nut may need a socket and a long bar.
There should be oil in the chain case.
If your engine is pre 1953, there is no seal behind the sprocket.
Trev.
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great, Trev.
Thank you very much. I´ve used the drift and hammer but with no success, but was in the neutral.
By the way, I´m selling a brand new oil seal for the primary! hehehehe....
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I have used am 18" plumber's pipe wrench with success, but have now changed to SRM hex-drive type cush nut. The tightened nut, according to SRM should get 65 ft. lbs. Very hard to achieve with a drift or c-spanner wrench.
Richard L.
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So, if my engine don´t use the seal, what could be the cause of the oil in the primary?
Just the ball+spring inside the engine, or could be something else?
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Ok, I know, but in the manual says 100cc in the primary and had at least 1 liter.
It was up half the cover with oil.
In this image we can see perfectly the line of oil, almost at half.
I don´t know if this is the normal.
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Was it that way when you got it? Meaning, maybe the last owner didn't know what he was doing. Or, did you fill it normally and it flooded to this level? I am not sure I will have the solution based on these questions, but it could help other members understand the problem and offer advice.
Ricard L.
P.S. Did you make it to Leigh Classics?
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I fill normally and flooded to this level. :(
The last time before putting oil I emptied the primary, took off the sump plate and empty the tank of oil. Even here I asked what was the way to put oil in the bike.
I put new oil and soon the primary was filled again. I was betting on the seal, but if my model do not have this restriction, now have a problem.
I make a phone call to the Leigh Classics but they don´t have the spares
I was looking for, so I don´t go there and buy online from Draganfly and Burton Bikes. :)
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Oil level rising, I see 3 possibilities only: trough gearbox shaft, crankshaft, hole in the crankcase. Time for some detective work !
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DT...
Removing this screw in the picture will give you the correct oil level in the primary chain case. Notice the rubber ring to prevent leakage.
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Thanks Lg.
Gf, Here´s my detective work:
Assemble all I need to put the bike working.
Leave the primary open, whithout the clutch.
(I was not able to get the engine sprocket off.)
And then, sit down having a beer and looking at the cranckcase until some oil appear. :D
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I use an air impact wrench (with about 100 PSI of air behind it) to take big engine and clutch nuts off. Usually you don't even have to lock the brake down, the inertia of the engine and gearbox is enough to hold it for the nut to come off.
Lannis
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I think the impact wrench implies a hex cush nut. Can you set the torque value when spinning on?
On another note, I am completely distracted today, with the Air Force Thunderbirds flying six F16s right by my window as they practice for this weekends Chicago Air and Water Show.
Richard L.
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The clutch nut I remove without problem after the Trev´s orientation.
Quite easy, in fact.
But the sprocket I don´t even have the tool.
And doesn´t matter, my engine does not have a seal anyway...
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sit down having a beer and looking
That's the best way to get things working again *smile*
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Well, the leak seems to be trough the cranckshaft.
It means I need dissasembly all the engine and I really don´t do this now.
Another problem, when I put the new clutch, nothing happens when press the clutch control.
Soon I realized the problem was at the CLUTCH PUSH ROD (67-3183).
My push rod have 12cm, anybody know the real size of this piece?
Another problem, I think I know why my bike used to have 2 friction plates and not 5.
Look the pictures, I put the Thick steel plate, 5 friciton and 5 steel. The last one almost doesn´t fit
and there´s no way to put the clutch spring plate...
Maybe the clutch centre and chainwheel is from another model or brand...
Thanks.
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Unless very different for '50, According to my meager knowledge it should have the domed outer cover with the bolts on the edge of the basket. See http://www.a7a10.net/BSA/techpics/clutch1.jpg
Your basket is simply not deep enough to accommodate all plates. You may try your luck by fitting whatever there is place for, and see if it works ok.
The push rod should protrude from the gearshaft, and move further out when clutch handle is operated. If not, it's too short for some reason, or set screw adjustment at the gearbox clutchlever is way off or even missing ?
Seem to remember a small roller steel ball in conjunction with the pushrod, may remember my plunger having a 2 part pushrod with a ball in the middle. But long time ago since I've done any clutch work, someone else may have better answers.
e
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e is right, That pressure plate is from a later swingarm 6-spring clutch. That basket isn't right either...not sure what it is.
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Right, here we go.
Here is a photo of a plunger clutch layed out. There should be one thick steel plate and four thin steels and five friction. The pressure plate is the correct one and goes against the last friction.
The thick steel is the first one to go in the basket, then a friction and a thin steel and so on. The pressure plate on the plunger models is also the last steel plate, it goes against a friction plate, not a steel.
Your basket is the correct one,these are the only ones to have a twin row chain, but at some stage in its life someone has machined off the flange that has the studs to hold the cover on. This should not be a problem, it will work ok as a wet clutch.
One thing to watch is the quality of the friction plates, sometimes the cheaper ones are thicker than the originals and can cause problems, I only use Surflex plates.
With the early plunger models without a seal the engine oil can get into the primary as you have found. This is not a problem but if your bike has sat for some time and has wet sumped then you need to check the level in the primary as well. Also only use a motorcycle specific oil that is suitable for wet clutches as a lot of car type oils have friction modifiers in them and they can cause problems with the clutch. Normally this would not be a problem but you will have a wet clutch.
Good luck.