Gear Box Oil query

[roo12]

Does anyone know if this gearbox oil would be ok for my bike - a Suzuki GP 100? The workshop manual recommends SAE 20W40 but I don't think that is even sold any more!

This is the oil I have in my garage

https://www.ebay.co.uk/itm/SILKOLENE-LIGHT-GEAR-OIL-4ltr-MOTORCYCLE-GEARBOX-OIL-/260880954970?_trksid=p3284.m263&_trkparms=algo%3DSIC%26its%3DI%26itu%3DUCI%252BIA%252BUA%252BFICS%252BUFI%26otn%3D2

But don't want to do an oil change if it's going to mess everything up.

Thanks.
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[Casper]

Me i would just use 10w 40 but thats me. You still get the 20w but it bloody dear.

[bodger]

The oil you have top quality stuff and is rated 10/40 so in my opinion it will be fine for the gearbox. The 40 rating is what matters so should perfectly ok.

[WannaBeDude]

I use ROCK Oil, caus it sounds the best out of all of um ..
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Jogging on, destination living.

[TGB]

in truth light gearoil is not suitable for syncro gearboxes. its mostly used in single speed transmissions. so i would say use proper gearbox oil for motorcycles with a rating of at least 10-w40 JASO MA or API SL or SJ. 20 w50 is still around any good motor factor will have it.

The GP100 is a good bike and a hardy one at that. their only real issue is the rotary disc valve can ware abit. but other than that their good bikes.

[roo12]

Ok brill, thanks guys, I guess I will go ahead and use it then.

The only thing that confused me was it saying:

SAE 10W-40 (Crankcase), SAE 75W or SAE 80W (Gearbox)

I don't understand what the second set of numbers are and if they mean it is unsuitable for my bike?

ROCK oil does sound far cooler but i just spent 7.99 on this stuff... Would be no cool to waste it.
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