Gearbox Oil

simon1221 · World Chat Champion Joined: 28 Jul 2004 Karma :

hi

i went to my local car spare shop to try and find a bottle of gearbox oil for my bike the guy said they dont do that type anymore, it was replaced with another one, but it is slightly different?

i really dont understand the system of 10w, 20w etc

can i not just put a closer one in:?

haynes manual: 10W 30SE

closest in shop: 5W 20SE
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DNA50 (sorry) ->> TZR125l >> GPZ500S

stinkwheel · Bovine Proctologist Joined: 12 Jul 2004 Karma :

The numbers are to do with the viscosity range of the oil over its designed operating temperatures. The higher the number, the thicker the oil.

I think the w referrs to it being suitable for use in winter but am not certain on that point.

The SE referrs to the resistance of the oil to damage due to shear stress, the further up the alphabet the letter after the S is, the more shear resistant (and therefore better). SE is old oil with a low shear resistance, I would seriously doubt if there is oil for sale today at less than SG rating, so anything you put in should be ok from that point of view.

So the 5w-20 oil is basically thinner than the stuff your manual recommends although broadly the same in the main part of its working temperature.

Given it is an older bike I would probably go for a 10w-40 oil in the gearbox. This is now pretty much the standard motorcycle oil and in an older gearbox I would probably err on the side of slightly thicker oil, it will make the gearshift appear a bit smoother if there is any wear in there.
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simon1221 · World Chat Champion Joined: 28 Jul 2004 Karma :

thanks, i will get some tomorrow
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DNA50 (sorry) ->> TZR125l >> GPZ500S

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

The S in SE stands for "Spark" as it is oils for petrol engines rather than compression ignition engines (diesels). SE is quite an old oil spec, but most bikes are not designed to need the latest greatest oil.

A 10W30 is an oil that acts as a 30 weight oil when hot and a 10 weight oil when cold (in Winter).

Personally I would say that the 30 bit is the most important bit on a 4 stroke, but on a 2 stroke gearbox I am not so sure. Would probably go for a 5W30 but failing that a 10W40.

All the best

Keith
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ZRX61 · Victor Meldrew Joined: 05 Nov 2003 Karma :

kasandrich · Trackday Trickster Joined: 20 Oct 2004 Karma :

simon1221 · World Chat Champion Joined: 28 Jul 2004 Karma :

i got the 5W30,

runs fine, very smooth and quiet compare to old (very old, grey coloured with bubbles in Thumbs Down

), it is semi-synthetic, i have not yet noticed any clutch slip

thanks for your help
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DNA50 (sorry) ->> TZR125l >> GPZ500S

Bomberman · World Chat Champion Joined: 17 Aug 2004 Karma :

simon1221 · World Chat Champion Joined: 28 Jul 2004 Karma :

it runs fine now, im not sure but i think the clutch did slip right after it was changed, but hasnt done it since (another 50miles), so thats great Thumbs Up

i only went because my usual bike shop got moved into another industrial estate and i couldnt find it cos they wanted to biuld anuther supermarket Sad

I still havent found it yet Confused

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DNA50 (sorry) ->> TZR125l >> GPZ500S