gearbox oil? why bother...

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Orsonoce

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Hi folks, have not been active on the forum for a while... busy with work, family etc...
I've had my bike for about 2.5 years now. Just finished some major works on her and am finally back on the road. Been probably riding something in the region of 3-4K km since I got it.
The only thing I have not checked since I bought the bike was the gearbox oil. I've changed 3 times the engine oil, changes the primary oil, but never bothered checking the gearbox... (don't ask me why) so thought it was just time for that (hoping to ride to the international rally in france next week, 1500 km return trip, so decided to change all the oils...).
Bought 1 lt Castol EP 90 (classic) on the internet.
Opened the drain plug and... nothing. NOTHING. Zero, nada, niente. empty. After a while I get some drops. All in all I got 20 cl of oil. that is 5% of what would normally be needed (410cl I believe)

Now, how can a bike ride for a few thousand km with NO oil in the gearbox without any major issues?
Mind, I am no light rider, when I have time to ride I squeeze all the horsepower from my babe, and yet nothing major seems to have happened to the bike.

what do you think?
 
I think you have worn all the bushes, bearings, shift forks and gear teeth much more than they would have been had they been lubricated.
 
I think...

Scary!

I've picked up two restoration projects, and neither of them had any gearbox oil left when I got to them.
GIven the way my MkIIA lets it out of the kickstart and gearchange shafts I'm not too surprised.
It uses more gear oil than engine oil, although a worsening tacho drive leak may even things out a little.
 
Orsonoce said:
Now, how can a bike ride for a few thousand km with NO oil in the gearbox without any major issues?
Click to expand...

You can't. It sounds like there was enough oil some of the time. I would not ride it until I inspected the gearbox. Seizing a layshaft / bearing can be hazzadous to your health.
 
L.A.B. said:
Are you sure the box is empty and that it hasn't been filled with a semi-liquid gease?

I guess anything is possible. Doubt it, but how would I check that?
Click to expand...
 
Orsonoce said:
L.A.B. said:
Are you sure the box is empty and that it hasn't been filled with a semi-liquid gease?

I guess anything is possible. Doubt it, but how would I check that?
Click to expand...
Click to expand...

You could remove the inspection plate/oil fill and look in.
 
Sometime it's better to be lucky than smart. Please forgive the referenced but gosh all mighty, you brought it to light, and quite frankly, you ask for it.

Anyhow, this sort of beg the question, "What's going to happen with oil in it?"

All kidding aside, you got away with it, apparently.

I have not had great success with fancy synthetics for the gearbox. I think your approach with the "classic" type of oil is good. I like the standard Lucas 80/90. No need to measure just fill to the lever plug.

One more question, You did drain from the drain plug and not the level plug, right.?
 
pvisseriii said:
One more question, You did drain from the drain plug and not the level plug, right.?
Click to expand...

That could be a very good question.

There is a little 'oil level' plug just behind the kickstart.
The bigger oil drain plug is down underneath, none too easy to see.
 
Rohan said:
pvisseriii said:
One more question, You did drain from the drain plug and not the level plug, right.?
Click to expand...

That could be a very good question.

There is a little 'oil level' plug just behind the kickstart.
The bigger oil drain plug is down underneath, none too easy to see.
Click to expand...

Oh, man.... :shock:
 
You should be able to see some oil down among the cogs with a flash light shown down the filler cap, which is like a inch below the useless level plug and the level I've learned to only fill it too or face a lot of mess until it seeks it natural level. ATF Dextron is what I like if staying in low gears long and hard. Obvious still good to go so top off and get back to us when ever it does misbehave.
 
Orsonoce said:
Now, how can a bike ride for a few thousand km with NO oil in the gearbox without any major issues?
Mind, I am no light rider, when I have time to ride I squeeze all the horsepower from my babe, and yet nothing major seems to have happened to the bike.

what do you think?
Click to expand...

In answer to your question, you cant now open the box and collect the bit's!
JohnT
 
Waiting for the report back from the author of this post, I would be happy for him if he was checking the level bung, rather than the drain bung. Triumph owners who did not have manuals must have had some scary moments, I remember the drain bung had a smaller bung in the centre that had a tube attached, this was like the reserve tap, it was used to indicate the level, but only worked during filling, or if the box was over full.

I can't imagine the gearbox bushes lasting too well, especially 300 km/ miles without oil. Ist gear bush for example is highly loaded even with oil present.

On a note of oil changes in the gearbox, I have found it beneficial to replace the oil more frequently, the gear oil does not get very hot and tends to get a bit of moisture in there, especially if you get caught out in wet weather.

Cheers Richard
 
stockie2 said:
I can't imagine the gearbox bushes lasting too well, especially 300 km/ miles without oil.
Click to expand...

"3-4K km" = 3-4,000 km
 
No way not to notice all the gearbox oil vacating the premises. I vote on the level plug.
 
thanks everyone for the contribution.
let me clarify a few points here.
Yes I did use the drain plug, and not the level plug. I did check in the inspection plate before anything else, there was nothing visible in it.
I've just measured the oil (black and horribly thick) I got out of it and it was better then described: I got 50-60ml out of it (still only 7% of total).

Let me tell you more about the history of the bike - as I bought it (3-4000 km ago) it used to leak 1 lt of oil in 1 hour use (serious), engine oil was leaking from everywhere, so maybe the gearbox unit was also leaking without me noticing (as there was oil everywhere then...). Then I fixed all the oil leaks. in the last 3000 km not a single drop of oil has been lost from the bike.
Now I've filled the gearbox with oil, yesterday I rode for a few km just to try it out - the bike makes a different noise, a better one, fuller I'd say, less metal rattling.
The bike has not lost a single drop of oil from the gearbox unit during the night.

2 options:
1) oil has not been changed or refilled there for the last few years and I bought it with 60ml of oil in it. Then it's been riding with no oil for God knows how long.
2) oil has left the gearbox unit during the 'heavy leaking season' so I 'only' made 3000 km with no oil.

In both cases it does seem it rode with virtually no oil in it for quite a while and at heavy conditions (not slow...).

Question is:
a)-Should have a big smile, go out there and ride hard and the bike will be thankful to me as finally there is oil in the gearbox and will go smooth and safe?
b)-Is this dangerous and I should open the gearbox and check everything before riding again?.
 
Personally, I couldn't not look. A gearbox failure is life-threatening and pulling in the clutch won't help. It's possible to have a good rummage inside the box without dismantling the primary drive but if you have to go the whole way, you'll wish that you'd loosened the other side off first.

Gearbox oil is not normally black. Could it be that some sort of moly product was being used ? This might have provided some protection if there was still enough to be picked up by the gears. I'd expect a box with no oil and worn gears to be singing like a four-wheel-drive Austin.

Early Nortons used to leak gearbox oil over the chain as the sleeve gear didn't extend into the primary chaincase but Commandos do. If your sleeve gear bushes are knackered then you could have lost oil into the primary case.
 
79x100 said:
Personally, I couldn't not look. A gearbox failure is life-threatening and pulling in the clutch won't help. It's possible to have a good rummage inside the box without dismantling the primary drive but if you have to go the whole way, you'll wish that you'd loosened the other side off first.

Gearbox oil is not normally black. Could it be that some sort of moly product was being used ? This might have provided some protection if there was still enough to be picked up by the gears. I'd expect a box with no oil and worn gears to be singing like a four-wheel-drive Austin.

Early Nortons used to leak gearbox oil over the chain as the sleeve gear didn't extend into the primary chaincase but Commandos do. If your sleeve gear bushes are knackered then you could have lost oil into the primary case.
Click to expand...

+1 When gearboxes run low on oil, it burns the oil. Rear differentials on cars/light trucks are most commonly ignored,
 
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