Oil quantity for laydown gearbox?

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I've drained the EP140 I had in it and am about to fill with 40 grade. I don't like the "fill till it runs out of the level plug" method as that usually ends up with oil all over the garage floor, especially as it's slow to feed through from the outer cover.

I've seen various quantities from 3/4 pint to 3/4 litre quoted - does anybody have a definitive amount? Edgar Franks is uncharacteristically silent on this point.....

Hi Ian- Main-Smith reprint…

Capacies Hi Ian-

Main-Smith reprint of Norton Singles Workshop Manual for 1950 -53

says 1/2 pint approximately - I believe this would be Imperial measure.

There is a small, square…

There is a small, square headed bolt on the laydown box which serves as level plug. remove the cover which gives access to the clutch worm, remove plug and fill until oil just drips out of the plug hole, tutn gears over a few times with kick starter and recheck level. Norton used a 40 grade oil in summer and 30 in winter. I happyly use an 75 / 90 gear oil instead.

Thanks both....

Charles - I was trying to avoid that when filling (no problem when checking) as the oil tends to fill the main casting slowly so by the time you see it running out there's loads in the outer cover waiting to drip through....

Richard - that looks good. Whicha manual is it - I'll have to get one from the NMM as I'm due this year's freebie!

Ian - It would be this one -…

Ian - It would be this one - sorry for the tatty appearance but it saw me through a bit more than 15 years - nearly 4 of which was a total restoration. If you are in a spendy mood grab the spares list as well .

Manual

And this -

Spares

Thanks Richard...

I have the spares list which is very useful - up till now for my many years of Norton ownership I've used the Edgar Franks book which was a birthday present to my father in 1948 - the year before I was born! I'll get a copy of that one from the NMM.

Ian - Ha - we are close to…

Ian - Ha - we are close to the same vintage then ! 1953 was the year my folks were blessed with yours truly.

Beware

Some may have noticed that the 75-90 and other 85-90 gear oils can foam like mad - strangely the old spec oils don't. When I saw it I was surprised, most probably OK where the aeration can rise out in a larger sump like on a car, but I was not going to take the chance in the confines of a Norton gearbox. Some are now starting to be advertised as 'low foaming'

The monograde EP's don't foam or aerate so badly as the modern stuff it seems

I would like my gearbox lubricated mainly by oil, not mainly by bubbles. Maybe nothing to worry about, but it was not confidence inspiring to see it happen.

I am rather suprised to hear…

I am rather suprised to hear that foaming is a problem with the multigrade oils. Usally any modern oil will have had to pass a foam test before being put onto the market. Excessive foam or air entrainment is usually due to overfilling and is worse with higher viscosity oils than with lower viscosity ones. Here anectdotal evidence seems contrary to published data.

Not that that is necessarily a reason to ignor it.

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