Slightly confused about geabox level of oil

[Ramjam]

Hi all
I just removed the right side casing which covers the clutch and i thought i would be terribly clever by not draining the oil via the plug but just by cracking the case and putting a bowl underneath.

But what came out was confusing.

Firstly, there was about a mug of water which i have no idea how it could have got in,

But more confusing is that not much oil came out. Can i assume that most of it is trapped inside the gearbox itself, which would explain why only the small amount in the clutch side came out?

thanks

MJ in Beirut

[pearljam724]

Not to strike fear into you. If you or anyone else filled the gearbox properly in the last few years ? I would be concerned about a blown crank seal. When these bikes blow a crank seal. The gearbox oil pukes out the gearbox breather ( snorkel) behind the oil pump at mid to high rpms. This may have happened to someone previous to you obtaining the bike and they never refilled it. Not knowing what was going on. But, without knowing your possession history ? It's a thing to look at. Just fill the gearbox to the cover side screw. Don't over fill or that will also cause the breather to puke oil. The side screw is the same depth of the bottom of the filler hole triangular cavity. Take it for a ride and see if oil pukes out the breather at mid to high Rpms. Water accumulates from condensation. A long period of someone not changing the oil often enough. It's very warm inside the gear box. That warmth meets cooler air creating condensation. Beacause the gearbox is not sealed from outside air. Hence the rubber filler plug and the breather. Most likely, the cover gasket stuck to the engine case or it moved from the cover. Blocking and preventing all of the oil from draining. Very common, believe it or not. Drain it via the plug or take the cover and gasket completely off.

[Ramjam]

Not to strike fear into you. If you or anyone else filled the gearbox properly in the last few years ? I would be concerned about a blown crank seal. When these bikes blow a crank seal. The gearbox oil pukes out the gearbox breather ( snorkel) behind the oil pump at mid to high rpms. This may have happened to someone previous to you obtaining the bike and they never refilled it. Not knowing what was going on. But, without knowing your possession history ? It's a thing to look at. Just fill the gearbox to the cover side screw. Don't over fill or that will also cause the breather to puke oil. The side screw is the same depth of the bottom of the filler hole triangular cavity. Take it for a ride and see if oil pukes out the breather at mid to high Rpms. Water accumulates from condensation. A long period of someone not changing the oil often enough. It's very warm inside the gear box. That warmth meets cooler air creating condensation. Beacause the gearbox is not sealed from outside air. Hence the rubber filler plug and the breather. Most likely, the cover gasket stuck to the engine case or it moved from the cover. Blocking and preventing all of the oil from draining. Very common, believe it or not. Drain it via the plug or take the cover and gasket completely off.

Hi
thanks. THat's useful. But i did ultimatly take the cover and gasket off. My question was is it possible for some oil to stay in the gearbox transmission side? This would explain why i only had a little oil in the clutch side even though the viewing hole screw was showing it was at the right level.

MJ

[yeadon_m]

Yes, the bulk of the oil will sit in the bottom half of the gearbox - I think, anyway - I've never tried draining it as you have - and will be drained by removing the vertically arranged drain bolt underneath (right rear, I believe). NOT the angled bolt which is for the neutral detent.
Mike

[Ramjam]

Yes, the bulk of the oil will sit in the bottom half of the gearbox - I think, anyway - I've never tried draining it as you have - and will be drained by removing the vertically arranged drain bolt underneath (right rear, I believe). NOT the angled bolt which is for the neutral detent.
Mike

thanks mate. that's what i suspected. Cheers

[rngdng]

If we are talking about the GT750, you can get coolant into the transmission from the seal between the cases for the bypass line, if I'm not mistaken.



Lane

[GTandcbr]

If you look ay figure 7-9-2 you will see a picture to explain the different oil levels i know its a 550 but your 380 is the same
http://www.3cyl.com/mraxl/gt/manuals/gt ... 550-47.htm" onclick="window.open(this.href);return false;

[Ramjam]

If you look ay figure 7-9-2 you will see a picture to explain the different oil levels i know its a 550 but your 380 is the same
http://www.3cyl.com/mraxl/gt/manuals/gt ... 550-47.htm" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

very interesting. But how does the oil, when you fill it up, from the clutch chamber enter the gearbox chamber? (it s not clear from the diagram). And how can you be really sure there is oil in the gearbox when the reference is the hole with the nut? (which is of the cluth side, so to speak). I suppose if you put in ecactly 1.5 litres, you could be sure, if it flows into the seconf chamber.

M

[jabcb]

If you look ay figure 7-9-2 you will see a picture to explain the different oil levels i know its a 550 but your 380 is the same
http://www.3cyl.com/mraxl/gt/manuals/gt ... 550-47.htm" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

I think the GT550 & GT380 are different.
I see the GT380 as more of a GT250 with an extra cylinder than as a smaller GT550.

The oil filler plug leads to the transmission on the GT550. With the plug out, you see the transmission oil level if you look in the hole.

This doesn’t work on the GT380 because the oil filler plug is in the case cover & you can’t see the oil when you look in the hole.
For why, see a pic of the back side of the cover.


And a pic of the right side of the GT380 crankcase.


Note: These are eBay pics that will go away.

[pearljam724]

The clutch and the gearbox share the same oil. That's why it's filled through the clutch cover.

[GTandcbr]

I stand corrected i thought 380 and 550 were similar design. fYI the oil on the 550 is washed around the gearbox by the gearwheel movement and in doing so escapes through a hole into the clutchcase. There is a plate on the inside which then drips it into the case.
I personaly empty and fill the gearbox using a measuring jug so i can examine the oil and see the quantity coming out and going in. I dont touch the level bolt.

[Ramjam]

I stand corrected i thought 380 and 550 were similar design. fYI the oil on the 550 is washed around the gearbox by the gearwheel movement and in doing so escapes through a hole into the clutchcase. There is a plate on the inside which then drips it into the case.
I personaly empty and fill the gearbox using a measuring jug so i can examine the oil and see the quantity coming out and going in. I dont touch the level bolt.

very wise. Good advice.

[jabcb]

I stand corrected i thought 380 and 550 were similar design. fYI the oil on the 550 is washed around the gearbox by the gearwheel movement and in doing so escapes through a hole into the clutchcase. There is a plate on the inside which then drips it into the case.
I personaly empty and fill the gearbox using a measuring jug so i can examine the oil and see the quantity coming out and going in. I dont touch the level bolt.

That advise is particularly useful for the GT380 since you can not check the level by looking down the oil filler plug opening.