Primary Chaincase drain cutaway- Plunger/early S/A

[duTch]

 I did a search for "Primary chaincase drain screw", and "Primary chaincase drain cutaway", but no glory...

 I'm trying to fix a persistent leak from my Plungers chaincase drain screw...but noticed on a spare outer cover, there is no complete cutaway as there is for the level screw (see photo).
  The cover I'm using is a bit chewed from chain carvings (old or recent ), but I think I noticed last it was off that maybe there was previously no cutaway there either- just disguised by the chain carvings.
 There doesn't appear to be a cutaway on the inner inner casting, but I know I had some busted screw lugs reinstated with weld (drain included), so my question;
    Is there is normally a cutaway in the inner case for the drain? Otherwise I can't see any way the oil can drain...?? (apart from leaking)
 A photo of good case would be nice if possible?? thanks in advance

[beezermacc]

I've had a look at a couple of chaincase covers and they are the same as yours. I've just checked the instruction manual and there is no provision for draining the chaincase on the plunger models. I think the level screw should have a fibre washer under its head. I sold my plunger a couple of years ago so the memory is getting a bit vague, hence the need to check in the instruction manual (BSA, not Haynes!). I noticed in the instruction manual, to be absolutely correct, the screw which fits in the level hole should have a red painted head. On the swinging arm models two of the screws are painted red. I dare say all the rivet counters will be out with their red paintbrushes this weekend!

[duTch]

 Thanks B-Macc, I knew about the redhead, but mine are all socket caps anyway...it's just the length that matters
  I looked in the service sheets, and could see no mention of draining oil before "...remove cover.." for clutch work, must be one job that gets done only after all oil has leaked out

 One thing I did find is the early A7 level plug is one screw closer to the front(2nd from front & higher) than later(3rd from front), hence an explanation for disputed oil levels??

  It's a curious thing and even though the gouges in mine allow oil to drain, I'm thinking to patch that and start again...but wondering how other Plunger cases look...??

[morris]

Could it be that the chain rubbings you're talking about gone through the case? Or maybe the outer case doesn't touch the inner above the screw hole? Oil don't need much to leak through (as if A10 owners don't know this...  )
From memory I'd also say there's no "drain" as such on my plunger's primary case and also that there's a flat at the same screw as yours. Maybe to give some clearance for the chain?
I have just a fibre washer under the level screw. Dry as a bone.

[Greybeard]

I have just a fibre washer under the level screw. Dry as a bone.

Ditto

[duTch]

 Ta Mossir and BG...
 

Could it be that the chain rubbings you're talking about gone through the case?

..Yep, definitely...

The cover I'm using is a bit chewed from chain carvings (old or recent )

Or maybe the outer case doesn't touch the inner above the screw hole? Oil don't need much to leak through (as if A10 owners don't know this...  )

...but that's how the drain cutaway works...?

From memory I'd also say there's no "drain" as such on my plunger's primary case and also that there's a flat at the same screw as yours. Maybe to give some clearance for the chain?

.....I considered that but there's plenty clearance, and I think the chain is well inboard from the outer anyway..

I have just a fibre washer under the level screw. Dry as a bone.

...Yep, same here....it's definitely leaking only from the drain screw rebate...leaks about 25ml/day, without riding anywhere; I've had a fuel tank issue, and other stuff to deal with (vocational interference) so haven't moved for three weeks- had to use the Gutzzi instead....  ...reckon I'll rip the outer off again tomorrow, and do more piccies...stay tuned

[Greybeard]

DuTch,

Sorry if I'm teaching my duTch granny to suck eggs...
Allen screws are likely to be a lot tighter than slot head screws so may be causing distortion of the casing(s). Try tightening with just a screwdriver bit.
Have you made sure that the mating surfaces are flat by light filing, (particularly around the threaded holes) or ideally rubbing against abrasive paper on a glass plate?
What sealant are you using? As mentioned before, I'm a big fan of Hylomar Blue.
If you remove the oil filler plug while the engine is running is pressure evident?

[duTch]

 Yo GB, actually not all eggs suck...to extract Emu egg stuff, it's necessary to drill(yes, drill) a hole in either end, and blow the stuff out from one end...only ever saw my Dad do it once, then he made some tukka from it...yahoo..back to chaincase..

 I put a bit of time and effort into ensuring the interfaces were fairly good...short of glass plate, eyeballed through to see the gaps against sunlight ...(yea kenow that stuff??)..trimmed the high spots with a 2nd bastard, but came up ok. I've used a paper gasket about ~0.2mm with three bond and silicone grease. Have had the cover off and on several times, and just slapped it back on and seals ok, but the leak is fairly definitely coming from the drain screw(and a bit from the tensioner bolt, but can live wit that)...wasn't too bad until I started to fix it... 
  Doesn't make any difference about the filler cap...it's leaking without moving...!!! Having said that, I patched it a bit the other week, maybe I missed some. If I have a chance tomorrow, I'll rip it off again for a dekko.


 

[morris]

Hiya duTch, I may have missed it somewhere, but does it leak at the mating surface or via the screw hole/head?

[duTch]

 

... does it leak at the mating surface or via the screw hole/head?

 As far as I can tell only from the screw...I've had it leaning to the left against the wall, so it's definitely flowing from the screw head (as per pic), I've laid it the other way onto the side stand, so will see how it looks in a few hours.

 Has dripped almost 50ml (2oz) in two days.

edit;

Sorry if I'm teaching my duTch granny to suck eggs...

  It's ok sometimes I need a jolt

[duTch]

 This thread want intended as a oil leak issue, but as that's where it went there's a conclusion. ....

Pulled the cover the other day(week- work's been interfering with lfe) to find when I counter-bored the drain-screw hole to add an' O ' ring to the screw head(as per an idea of Richard L), the outer case lobe was a bit thin where it had been rebated and broke through (photo 1).
  I bodged it up with some'liquid steel' epoxy-but didn't let it harden long enough and the other ' O ' ring under the screw head prolapsed through (photo 2)and caused the leak.... So I had another go with a different product and it seems to have worked OK(photo 3&4)....I used a Aussie product, 'Ultra-Bond'http://www.ultrabond.8m.com/ sounds similar to 'Lumiweld' or 'Technoweld' or something, and a Swedish product that I can't find reference to again.

Trouble is, I had a scraping noise when I cranked it over after replacing the cover and oil. ...drained oil again and pulled the cover to find I hadn't dressed the repair enough(at all) and it was rubbing on the chainwheel clutch cover flange (Photo 5)...Easy fix (with a bastard file), and for now after a week or so is staying dry (with just a fibre washer)

 So if anyone has an opinion at some stage of the original query when they have the outer off..?? Not important, just curious how the oil drains without a cutaway

[muskrat]

G'day duTch.
I see you've made a degree disc too. Makes timing a lot easier.
Cheers

[duTch]

 Yeah Musky- made it when I had the cover of about ten times ago. .. beginning of the year. Still haven't rigged a pointer for the light though, maybe next time.
 A bit off topic, but  found the reference to the other Low temperature aluminium welding product; "Alutight"
 Second comment on here. .... http://www.bsabantamclub.com/forum/general-discussion/lumiweld, and a good review from Trev on lumiweld here;
  http://www.b50.org/phpBB2/viewtopic.php?t=2025
 Hope you don't mind Trev- save you doing it

[shabashow]

My 52 plunger primary has no cutaway for draining, either. It can be a bit of a PITA to have to remove the entire cover, just to change the oil. I suppose just slackening off the screws might allow drainage without disturbing the gasket too much and causing future oil leaks. I don't want to start filing away at my chaincase just yet.

[duTch]

 It's heartening to know that I hadn't imagined it, but as my outer had already been chewed enough by loose chains to allow it to drain, I didn't really think about it.
  It's nice to have a cover that's in good original condition, but depends if you want to make it a less messy job.
 One thing I would consider (if I have to),  is to drill a small hole(~3/16"?) in both sides of the very bottom of the drain screw lobe to allow easy drainage....?