The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: DaveB500 on 05.10. 2009 12:53

Title: Oil Leak, Primary Side.
Post by: DaveB500 on 05.10. 2009 12:53
Hi Guys.
I have an oil leak on my 1960 A7SS.
The leak is from the primary side, between the Primary case and Gearbox.

My guess its the seal behind the clutch.
In the service book this is listed as  felt washer.

Is that the case?
Or is there an oil seal as well.
I know old bikes do leak, but this is quite bad, only happens when I actually ride the bike, if its left ticking over then that part of the engine is dry.

The only other leak I have is from the rocker cover, and that looks an easy fix. Opps shouldnt have said that.

Dave
Title: Re: Oil Leak, Primary Side.
Post by: bsa-bill on 05.10. 2009 14:49
HI David
Yes - behind the clutch is a sliding plate and behind it a felt washer.
The sliding plate has an oil thrower on it, these sometimes wear off.
If the plate is at fault fixing will require dismantle/removing the clutch, before going that far best to check oil level in the primary case, you only need enough oil in there for the bottom run of the chain to catch.
The sliding plate is held by two stepped bolts that allow the plate to slide when the primary chain is tensioned.

All the best - Bill
Title: Re: Oil Leak, Primary Side.
Post by: dpaddock on 05.10. 2009 15:26
The location you describe is also the region where the engine breather exits.

David
Title: Re: Oil Leak, Primary Side.
Post by: A10Boy on 05.10. 2009 16:19
Dave, the best way to check this is drain the oil from the primary chaincase and replace it with ATF fluid which is great for clutches and is coloured red so you can see which oil is leaking.

Also, if the crank seal is leaking behind the cush, that can pressurise the chaincase and blow oil from behind the clutch.

Andy
Title: Re: Oil Leak, Primary Side.
Post by: DaveB500 on 05.10. 2009 16:33
Thanks guys I will check, out both of these.

The Oil coming out is clean, and doesnt look as if it has been through the engine, but there could be some pressure build up I guess.

Dave

PS now posted a photo of the bike as I recieved it.
Title: Re: Oil Leak, Primary Side.
Post by: muskrat on 05.10. 2009 19:57
G'day Dave, the other spot there where oil can escape is between the g/box main and counter shaft. If you use g/box type oil you can smell the difference. So if you use ATF in primary you have 3 possibilities, engine oil = breather, red oil = primary, smelly oil = main shaft.
A fellow down in Melbourne makes a sprocket nut with a seal to stop the later.
Cheers.
Title: Re: Oil Leak, Primary Side.
Post by: cus on 05.10. 2009 21:45
G'day Muskrat,
I'm interested in this sprocket nut, are you able to mention who has them,

regards, Cus
Title: Re: Oil Leak, Primary Side.
Post by: muskrat on 06.10. 2009 05:35
G'day Cus, John Scerri, Lytedrive, lytedrive@optusnet.com.au I am getting a belt primary from him and he sent me a nut to try. The only prob is that if you use a tri 4 spring adapter it is a mm too thick. No prpobs for std clutch. I let him know and he is sliming it down.
Cheers
Title: Re: Oil Leak, Primary Side.
Post by: cus on 06.10. 2009 07:44
Thanks Muskrat,
I'll get in touch with him,

Cus
Title: Re: Oil Leak, Primary Side.
Post by: Johnny J on 30.11. 2014 13:34
Hi!

My name is Johnny and I am new to the forum (and BSA motorcycles. :-))
Recently I bought a A10 Golden Flash 1960 and I also have a problem with an oil leak between the primary and gear box.
It´s quite a severe leak, dripping when standing still and pouring after a ride. I actually checked the primary oil level yesterday for the first time and it was almost empty.

Could someone with more experience than I make an educated guess by the picture if it is the oil seal behind the clutch that needs replacing? In that case, is it spare: 67-3067?
I have marked visible drops located between the primary and chain guard in red:

Title: Re: Oil Leak, Primary Side.
Post by: bikerbob on 30.11. 2014 16:49
That part No. 67-3067 is the gearbox mainshaft oil seal if you are correct in where the oil is leaking from then I suspect that you may need to replace the felt seal which is behind the clutch along with the sliding plate also you may want to look at reverse scroll that fits on the end of the clutch sleeve the part No for the felt seal is 42-7504 the No for the sliding plate is
66-7520. the reverse scroll No 65-3833 in the parts book it is called a clutch sleeve collar.  You may not need all of the above but to check you will have to remove the outer primary case and remove the clutch completely to check .
Title: Re: Oil Leak, Primary Side.
Post by: muskrat on 30.11. 2014 19:21
G'day Johnny,  *welcome*.
I'm leaning towards the g/box seal, if its as bad as that. If it puddles after a good run and is parked on the side stand its g/box seal.  Try the ATF in the primary to see the colour of the oil leak.
Cheers
Title: Re: Oil Leak, Primary Side.
Post by: RichardL on 30.11. 2014 19:33
Welcome. Looking forward to pictures of the whole bike. What is it that led you to buying an A10? (Really, we already know the answer, but like to hear others confirm the rationale for our obsessions.)

Though it won't be the reason for your leak, while you're in the vicinity, check to be sure there is a spacer (usually four or five washers) between the frame tab and the lower rear ear on the inner primary cover. If none, and it's bolted, the inner cover can get bent or, maybe, fracture.

Richard L.
Title: Re: Oil Leak, Primary Side.
Post by: Johnny J on 30.11. 2014 21:32
Thank you all for your suggestions, I have a steep learning curve ahead, bought the bike 3 days ago. :-)

I will start with the ATF, if the oil comes from the primary would that mean that the gear box seal might be OK and it¨s the felt washer thats faulty? (Might be a stupid question...)
Can also mention that I might have overfilled the primary after finding it empty, filled it up to the lower screw level on the primary outer cover.
Edit: Forgot one important thing, when it was empty there were no leaks suggesting it is the primary oil that's leaking.

I am used to and spoiled by the relative simplicity of electric motorcycles, more or less 3 parts, motor, controller and batteries, so more or less advanced mechanics requires a different way of thinking. ;-)

Heres a pic of the bike, not completely original as you can see:
Title: Re: Oil Leak, Primary Side.
Post by: bsa-bill on 30.11. 2014 22:19
Smart bike Johnny J

Don't worry about asking questions daft or otherwise, we've all asked them

You may have over filled the chain case, there is a level plug arrangement on your bike. it can be seen in the photo you posted, to the right of the two red arrows between the silencer and the lower frame tube - black arrow in pic
the large nut screws into the chain case and has a tube attached to it. the top of the tube is the correct oil level, the small stud blocks off the tube.
to fill the chain case - remove the small stud - fill the chain case until oil comes out of the hole - that is then at the correct levl.
If you've over filled it just removed the small stud and let oil out until it stops,
The method you used
Quote
filled it up to the lower screw level on the primary outer cover
was the method used before the level plug system was incorporated
Title: Re: Oil Leak, Primary Side.
Post by: duTch on 01.12. 2014 00:24
Hiya Johnny- if you do need to change the chaincase seal, it's not much more to do the gearbox seal also. .... Just need to pull the inner cover.
    Only thing is you'll need a special nut undoer...!
Title: Re: Oil Leak, Primary Side.
Post by: muskrat on 01.12. 2014 01:05
G'day Johnny.
Bike looks good to me. The only thing I'd change is the front guard.
Once you've got the correct level in there (preferably ATF). Take her for a good ride (30-40 miles) and have a look.
Another thought is that there was a bad batch of clutch sleeve collars getting about with the scroll in the wrong direction. Instead of throwing oil back in it would throw it out *eek*.
Others here have modified the sliding plate to take a proper seal and removed the scroll.
http://www.a7a10.net/forum/index.php?topic=5117.msg35077#msg35077
http://www.a7a10.net/forum/index.php?topic=3685.msg26381#msg26381
Cheers
Title: Re: Oil Leak, Primary Side.
Post by: Johnny J on 01.12. 2014 20:44
The method you used
Quote
filled it up to the lower screw level on the primary outer cover
was the method used before the level plug system was incorporated

OK, I guess I over filled it by 1.4L!
That would propably make the tightest primary leak...

Will get some non-freezing days later this week, I'll go out for another drive and see if the oil pours out when I have the correct level. I guess it will but it's worth a try.
The previous owner had a theory that since the bike had not been driven for a long time, the gaskets had dried out and needed to be wet again to stop leaking, I doubt this though, I propably have to change the parts.

Title: Re: Oil Leak, Primary Side.
Post by: duTch on 01.12. 2014 21:45

 Might be ok but you may need to wash some oil off the plates...Could make it be a bit slippy/draggy. ... Maybe
Title: Re: Oil Leak, Primary Side.
Post by: Johnny J on 14.03. 2015 14:10
The weather has been quite nice lately so I've been out riding a few times, love it!

I know the subject has been up countless times, but I still get leaks from the primary after a ride, not so much now, but still.
I have put a reverse scroll on that was missing and changed the sliding plate, replaced the felt washer with a rubber type one, put ATF in only enough to touch the chain.

What else can you do without major rebuilds?
Or just live with it?
Title: Re: Oil Leak, Primary Side.
Post by: duTch on 14.03. 2015 16:41

 Mine doesn't seem to leave it's mark when I'm out trekkin' and stop for a while sometimes an hour or some..but back at camp it likes to *** on home turf..so I put a drip tray(paint tray) under- when I remember.
 I guess you could say that for the moment I'm pretending I've got used to it...!!!
 Still working on it too. *conf*
Title: Re: Oil Leak, Primary Side.
Post by: nimrod650 on 14.03. 2015 19:14
you know what they say about british bikes they leak oil before you put it in just joking i had to replace felt disk on my rocket  no more problems after 3 yrs
Title: Re: Oil Leak, Primary Side.
Post by: RichardL on 16.05. 2015 18:16
I try not to start a new topic when an old one will do.

This morning, I decided it was time to stop the oil leaking from my primary cover. I'm fairly sure it was getting past the cheap paper gasket and sealer and probably not (so much) past the fill-level and drain screws. Nevertheless, I would like to fit sealing washers under those screws. Not finding fiber at my most convenient hardware store I opted for nylon. Of course, no off-the-shelf washer would have the necessary small OD with the 1/4" ID. After grinding one to what I thought would be the right OD, when I went to fit it, I noticed that those recesses appear to have two different counterbore diameters. The larger being that of all the other  screw recesses in the cover and the smaller just clearing the socket head and creating a shoulder in the screw recess. There is no way I could create a washer with a small enough cross-section to fit the smaller counterbore (at least it looks like a counterbore). Does anyone know if the original level and drain screws had custom heads that sealed somehow with this extra shoulder in the screw recess?

Richard L.
Title: Re: Oil Leak, Primary Side.
Post by: RichardL on 16.05. 2015 20:14
A picture is worth...etc.
Title: Re: Oil Leak, Primary Side.
Post by: duTch on 16.05. 2015 23:41

  Can't really tell from the photo, but am thinking maybe it's distorted from zealous tightening in the past, and worn to the size of the screw head...? As far as I can tell there's only two sizes the larger (by my measuring) @ 25/64" and the main bore @17/64" or maybe 9/32", don't have that size......I may be wrong

 As it happens, I only know that because was playing with a spare cover yesterday, to rectify the same issue, it seems mine leaks mainly from the drain screw, and some from the chain adjuster screw (Plunger model)...I've done what you did- but with a fibre washer, they are very tricky to grind, and still doesn't work
 My next trick, is to countersink the main bore with the 25/64 bit and leave a thin shoulder for the socket cap screw, and add in a 1mm section 6mm 'O' ring. 
 
 
Title: Re: Oil Leak, Primary Side.
Post by: RichardL on 17.05. 2015 00:42
Dutch,

I thought the shoulder was rather obvious in the expanded photo and very clear if you can zoom in further, but, no mind. The idea about zealous tightening did occur to me, but I would expect it on more holes. Also, i don't think it would run so deep.

What I am going to try is to grind an o-ring groove into the circumference of the socket head and have the o-ring seal against the wall of the shoulder.

Richard L.
Title: Re: Oil Leak, Primary Side.
Post by: duTch on 17.05. 2015 02:06

 Ok had a better look, as per doctored photo...and,

 
Quote
grind an o-ring groove into the circumference of the socket head and have the o-ring seal against the wall of the shoulder.

 I might have thought of that but discounted it because of laziness, or forgot....or having measured the socket cap decided there isn't really a lot of material(~1mm) if the groove is at the landing end, but now you remind me I did buy some 8mmx1mm 'O' rings to do it, but think I'll do a groove towards the top and the countersink as well....you got me going now
 
 *wink2*
Title: Re: Oil Leak, Primary Side.
Post by: RichardL on 17.05. 2015 02:20
In the photo, the first ID step-down looks like a copper-colored band about 4mm high. Of course, it's not copper. Oh, and I say "grind an o-ring groove" because I don't own a lathe, but I do own a Dremel grinder and a vise to hold it in.

Richard L.
Title: Re: Oil Leak, Primary Side.
Post by: duTch on 17.05. 2015 02:47

 
Quote
a Dremel grinder and a vise to hold it in.

 Forget the vise, put it in a drill, so it spins opposite to the dremel- works heaps good(very well!)... I acknowledge that tip to a who guy did a custom jobbie in a ragazine, years ago
Title: Re: Oil Leak, Primary Side.
Post by: bsa-bill on 17.05. 2015 08:30
you don't happen to have an early inner primary case on there do you, the one with the level screw on the third hole, just a thought as those cases had an open top screw hole , if you know what I mean
Title: Re: Oil Leak, Primary Side.
Post by: RichardL on 17.05. 2015 14:44
Bill,

My level screw is the first behind the 5/16ths screws and the third is the drain. There's a hole in the top of the thread bump for the level screw in the outer cover and a cutaway in the drain bump (there must be a better word than "bump"). There happens to be a picture of my inner primary, here: http://www.a7a10.net/forum/index.php?topic=368.msg58817#msg58817 ) Not sure what this might have to do with the shoulders inside those screw recesses.

Richard L.

EDITED
Title: Re: Oil Leak, Primary Side.
Post by: bsa-bill on 17.05. 2015 16:29
Quote
Not sure what this might have to do with the shoulders inside those screw recesses.

Nothing would be the short answer Richard.
I did have a similar problem with an inner that was wrong for the bike (bike was a 59 - not sure when they changed to the combined level drain plug)
anyway I just popped an O ring over the screw until I got a later type inner
Title: Re: Oil Leak, Primary Side.
Post by: trevinoz on 17.05. 2015 22:06
The fibre washers are available from Burtons, I think. I got some last year.
They are about 3/8" o.d. and .085" thick.
Title: Re: Oil Leak, Primary Side.
Post by: duTch on 18.05. 2015 00:00

 I remembered that I ordered some of the correct fibre washers from DragAnfly a few years ago part# 67-1709, but they sent me wrong ones... *pull hair out*
 Yo Bill I was assuming it was the early Swing arm type, same as Plunger and maybe Longstroke..?

  Richard, I went ahead and cut the 'O' ring grooves in level and drain screws (took about two minutes), then remembered why I didn't bother to do it before- is because the drain screw doesn't sit deep enough in the hole so I hand countersunk it, will do it properly and a bit deeper to accommodate an 'O' ring, on a drill press next time the cover is off.
   The level screw well is ok, so should suit so long as the counterbore is smooth enough (mine has not apparently been leaking, but did it anyway and left the fibre washer in there)

 Pasted a pic of the inside of the spare (Plunger type) cover- would've been a good one except for a few battle wounds. Funny thing is, it only has a cutaway for the level , not the drain- that must be on the inner....never noticed...?

Title: Re: Oil Leak, Primary Side.
Post by: bikerbob on 18.05. 2015 13:29
As regards oil levels I have found that the best way is to ignore the level screw and measure out the correct amount of oil as per the workshop manual and pour it in, as if the bike is not perfectly level then you can overfill or underfill. I use the same procedure for the gearbox.
Title: Re: Oil Leak, Primary Side.
Post by: nimrod650 on 18.05. 2015 18:57
 same as biker put in correct amount as per manual
Title: Re: Oil Leak, Primary Side.
Post by: bsady on 26.01. 2018 20:41
I made a dipstick to set the level. through the filler cap vertical, when the oil was the correct level buy the cover screw I dipped it, marked it and now just fill to the level without the worry of a leak every time I check it.
Title: Re: Oil Leak, Primary Side.
Post by: Black Sheep on 26.01. 2018 22:00
I kick the bike over with my finger touching the underside of the chain through the filler hole. When I get oil on my finger, there's enough in. Best press the mag cutout when doing this.
Title: Re: Oil Leak, Primary Side.
Post by: RoyC on 27.01. 2018 06:39
I kick the bike over with my finger touching the underside of the chain through the filler hole. When I get oil on my finger, there's enough in. Best press the mag cutout when doing this.
How can you tell if the oil is from the oil bath and not from you pouring it over the chain when filling ?
Title: Re: Oil Leak, Primary Side.
Post by: duTch on 27.01. 2018 09:22

 I gave up on all that and figured it's easier to shine some sunshine (from my 'sunshine storage box', or reflected from a mirror), or failing that, a artificial light source straght down into the casing so I can see it and add as necessary roughly to the level. Ffs as long as there's some in there that can be seen, it'll do the job- it leaks out anyway so just check it occasionally