Hitchcocks Forum

Hello
Is it OK to use EP90 oil in a late fifties 350 bullet(gearbox no AGL 569),or should I use 00 grease and top up with 90 oil as required.

OO grease and top up with ENGINE oil

I use EP90 in all my Redditch boxes even early (pre 55) ones. They are fine and don't leak as long as the kickstart bush isn't worn! REgards, Mark

You can get a 120 gearbox oil - sort of in the middle.

There is a theory that EP oils can damage the bronze bushes which is why engine oil is recommended. However, I used grease and EP90 in my 1999 bullet when I rebuilt the box and so far it is working fine without leaks (Bronze bushes and unsealed bearings).

I deliberately didn't mention the EP eats bushes story as it isn't true. It might have been in the 1930s but not for many years now. Jack Gray nailed this some years back with the help of the research team at Castrol. So rest easy! REgards, Mark

There is no point in putting that smelly substance in a straight cut gearbox. The EP stands for extra pressure and is designed for helical gears. The 00 grease is what the boxes were designed for and with the older boxes was the only stuff that didn't leak out in a near constant stream. With my Indian made 4 speed box which doesn't leak so fast I use straight 50. 90 is a very suitable weight of oil but unless you like the smell of sulfur I wouldn't bother with the EP.

Hi guys--- EP stands for EXTREME pressure as found in Hypoids, bevel boxes etc or where there is a shearing motion acting n the oil................This might help}--- http://en.wikipedia.org/wiki/Gear_oil -----------

Also worth mentioning that gear oils and engine oils use different numbering systems so 90 gear oil is not way thicker than 50 engine oil.

I have EP90 on the shelf because l use it in my everyday bike, a BMW. When l use it in my Redditch bikes l do so knowing it is over spec not unsuitable, a big difference. A friend of mine bought an Excelsior Manxman 350 and rode the nuts off it for 3 months before the clutch had enough. When the gearbox was opened there was no oil except the film of Morris EP90 left when the previous owner forgot to refill it after the last service! The gears on the Albion box (nearly identical to the Bullet) were undamaged. I don't think engine oil would have survived and that's why l use EP. REgards, Mark