Primary case seal?

[route 66]

In the parts book under 'primary cover' there is a part nr 67-1709 which shows as a seal.This is at the very bottom of the case.I have never seen or removed these.I assume they are to stop oil leaking down the screws holding on the cover.Is this why all my bikes have leaked from there?

[Greybeard]

I currently have tiny fibre washers on the drive side case screws.

[rocker21]

converted my primary drive to a belt, so no oil or gasket needed. much quieter and smoother.

[route 66]

converted my primary drive to a belt, so no oil or gasket needed. much quieter and smoother.

I would like that too but does it not involve removing material from the casing for heat loss?

[rocker21]

not really unless you go racing, just leave the drain plug out, done lots of miles without problems and you can find neutral at the traffic lights.

[Black Sheep]

My A10 primary chaincase hold oil for years on end. Shouldn't need drastic measures.

[sean]

In the parts book under 'primary cover' there is a part nr 67-1709 which shows as a seal.This is at the very bottom of the case.I have never seen or removed these.I assume they are to stop oil leaking down the screws holding on the cover.Is this why all my bikes have leaked from there?

never had a problem with oil leaking past the threads but pipe dope paste on the screw threads  would likely do  the job

[JulianS]

67 1709 is just a simple 1/4 inch bore fibre washer - my parts books describe it as "oil level and drain washer (fibre)"

I buy them from ebay. Very cheap.

[Swarfcut]

 It all depends which primary cover you have. This fibre washer was used on all A series bikes, Longstroke, Plunger, S/A where the cover has cutaways for the level and drain functions  The washer seals the head of the retaining screw against the cover.

 Later type of S/A Primary cover to hand has a standpipe and plug for level and drain so  no cutaways, so in theory an additional seal under the screw head  is unnecessary. This cover also has the access plug for clutch adjustment. However, washers are still shown in my 1961 Parts Book. So again there may be variations in detail machining to the covers and in view of the low cost of the washers could be it's a belt and braces approach on the later engines, but as GB has done, a few extra will help to keep the oil in and off the parquet of the living room.

 Removing the primary cover of a newly acquired fully restored RGS always carries the risk of breaking the magic spell and finding that the clutch is actually an old knackered 6 Springer from an M20......

Swarfy.