Hi, new to the forum and ownership of my BSA. I have a 1964 BSA A50 star but have the A65 engine! Love the bike. I am understanding the basic maintenance of the bike. Regarding the oil for the gearbox, everyone I speak to seems to have a different opinion of what oil to use in the gearbox. So my question is.... What oil / grade should I use in the gearbox?
welcome to the forum,
you have asked a question now await a dozen different answers.
the difference between A50 and A65 will not make any difference to the oils used.
I would say EP90 or SAE50 they are around the same. Personally its Castrol.
Hi Steve,
Welcome to BSA ownership. If you follow the spec. in the manual it seems to suggest a thickish engine oil but there are good gear box specific oils out there. I believe that the molecules in gear box specific oils are designed to be squashed and chopped by the action iof the gears and can reform to maintain the integrity of the oil.
I would go for the EP90 as I have used this for many years and many thousands of miles.
Dave.
Thanks gents, really appreciate your knowledge and replies. I shall use Ep90 or EP80w 90.... In your experience which level of oil is best suited for gearbox (may not matter), Ep90 at level API GL4 or GL5?
I tend to stick with Castrol as it is formulated to the old recipe, most of the Castrol classic range was reformulated to match the old as requested by classic car clubs . At their request and with the thought of future requests by classic car and bike groups , the range was expanded. This ensured that the correct ingredients were included for our old phosphor bronze bushes and bearings rather than modern Japanese style roller bearings.
Presumably Morris oils and others have followed on by now.
I use Morris AG90, non EP gear oil in my A10 gearbox.
https://www.morrislubricantsonline.co.uk/golden-film-ag-90-gear-oil.html
There used to be a yardstick, if you've got phosphor bronze bushes in the gearbox , then use GL4.
Remember, 50 odd years ago oil technology was very basic, motor manufacturers used what was around,
Monogrades sae 30,40,50.
Even 20-50 was in its infancy