oil leak from crankase to chaincase

[eugenius]

Hi all, I have an oil leak from the crankcase into the chaincase of my BSA A10. Almost all oil have drained out of the chaincase when removing the draining screw. What can be the cause? Thanks for your help

[muskrat]

G'day Eugen.
Sounds like the crank seal has gone west. It can be replaced by removing the primary cover, cush drive. You'll see it held in by a few punch marks.
Cheers

[limeyrob]

Had it been standing long?  If the wet sump valve is not working then the crank case will fill up and drain into the chain case once it reaches the seal if the seal is not working.  Of course the oil should not be filling the crank case in the fist place.
If you've been using it then its blowing past the seal and it would take quite a time to fill the chain case.

[eugenius]

Goodmorning and T
thanks friends, unfortunately I am seeing that the two screws fixing the chain case to the crankcase are loosen and both stripped! That's look like a disaster. To dismount the engine sprocket nut should it be turned clockwise or anticlockwise? and how without the appropriete tool?. Ciao

[muskrat]

G'day Eugine.
That's a bugga.
Righty tighty, lefty loosey. Anticlockwise. A "C" spanner or punch & hammer You could repair those threads without an engine strip. Timeserts or alike would be my choice.
Use grease in the flutes of the drill and tap so no swarf enters the motor. After drop the sump plate and give it a good flush. The only problem I can think of is they might protrude into the case and foul the crank webb. The shortest Timesert is 0.35".
Throw a new seal in while your in there.
Cheers

[eugenius]

Dear muskrat! Precious advices giving me some more breath! What's your first name? How should I call you? It will be difficult to come in Australia to shake your hand but I would like to do so and drink a beer together. Ciao

[berger]

eugenius i will drink muchos plenty with you

[eugenius]

Hi berger! It will be a pleasure! A crazy idea might be to make it true all together sometimes...

[limeyrob]

You can heli-coil in situe using the grease trick and you can always take the sumpl plate off and squirt brake cleaner in the holes and flush it though.

Is it the two Whit bolts that are wired?  These strip because they get pulled out, I have too that are waisted in they have been pulled so hard.  I think its if the inner chaincase spacer (42-4792) to the frame under the rear is not right then the case pulls away from the engine and its leveraged.  They don't need to be tight, a would do them hand tight and wire them.

[muskrat]

G'day Rob.
If you use helicoil the problem is the tang that has to be broken off. I magnetize the punch to catch the little bugga.

G'day Eugen.
This is what the Forum is all about. Helping others keep their A7/A10's on the road.
Most people call me Musky.
Cheers

[eugenius]

Thanks limeyrob, your hypothesis seems sound provided both screws were found simultaneously stripped! I will check the inner chaincase spacer to optimize the distance once tried to repair the screws sites by helicoil or timeserts.

Yes musky and friends, that's the role of this forum, great job! Ciao
 

[limeyrob]

The big washer / spacer between the case and the engine seems to be only one thickness but the small one at the rear to the frame seems to be where the adjustment is done. I assembled mine a few weeks ago and it only needed a couple of washers.  I don't think its a good design, once the cover is on the case is very stiff.  Its anchored to the frame at the rear by that bolt and if there's any movement its a big lever.  I'm wondering if that rear bolt should be left loose with a rubber sleeve or grommet?

[muskrat]

G'day Rob.
When you think of it it's just like the head steady and engine plates. Just another place to improve rigidity and keep placement of the felt seal and scroll on the mainshaft.
Cheers

[eugenius]

Yes Limeyrob it seems likely that the posterior spacer fixed to the frame might be a cause. However I am concerned that by leaving loose the rear bolt with a rubber sleeve or grommet might increase rather than reduce the oscillation of the chaincase once firmly fixed only anteriorly. Ciao 

[limeyrob]

You may be right, I'm not sure what the answer is but the design is not ideal.