Gearbox oil / primary case oil? Gasket?

[Chris B_LAPSED]

Hi so had the 1953 G9 a week and getting round to doing bits and bobs. Drained about a egg cup full of gearbox which was like mayonnaise. Angry face..... then iv noticed the oil below primary chain was rusty colour so took the primary case of and going to renew the gasket (it was leaking of course) and top up everything as required ..... so my questions are please

1. Whats best gearbox oil to use?
2. What's best primary case oil to use
3. What would recommend for a new gasket for primary?

Many thanks

[dave16mct]

Straight 50 in the gearbox or some use Hypoy 90. Straight 20 or 30 in the chaincase, some use ATF ( I use 20/50). Get the improved seal from club spares. It doesn't leak. You need to add a washer or two to the centre spacer.
Dave.

[Chris B_LAPSED]

Thanks for that dave ill order the new seal.

I have some spare 40 oil would this be ok to use in the chain case? Or shall I order the 30. Do you know how much it takes to fill the primary case and gearbox?

Many thanks
Chris

[dave16mct]

It's a bit heavy but I know some put 50 in there. I'd go for some 30. Only put enough in the chaincase to just touch the very bottom of the chain. 1 pint of 50 in the gearbox. There's a level screw so you can't go wrong.
Dave.

[Chris B_LAPSED]

Thanks dave I'll have a search for some 30 & 50...i'm trying to locate on the spares site the rubber seal that goes over the centre bolt on the inside of the chain case? mine is do a change...

[dave16mct]

There wasn't a rubber washer originally. Just use a fibre washer if you like but you will need a washer or 2 to space it out for the new seal.
Dave.