Gearbox making a noise.

[mark1]

Looks like it's going to be expensive



Not got the scooter back yet but it looks like the rear hub bearing has gone and taken the gearbox out and layshaft with it.

Started losing power on the m74 coming out of Glasgow yesterday on the way back from mull. Pulled into services and it made a horrific noise. I decided to strip it while waiting for recovery.
Ah well at least I made it up there.

[Donnie]

bugger certainly sounds bad

[mark1]

The recovery people delivered the scooter back yesterday and I stripped it down last night. Only one way to put it, it's a mess.

Layshaft, 4th, 3rd 2nd gears, gear cluster, sliding dog all cooked. rear hub bearing shot as well.

So what caused it? Rear hub bearing seal not broken, chaincase gasket still ok, Mate was behind me and couldn't see any smoke so drive side oil seal ok (i'll do a leakdown test tonight to confirm) So where did the gearbox oil go.

I checked and topped the oil up on wednesday night before setting off to Mull. rode 340 miles there with no problems, did around 60 miles around the island, rode home, got to Glasgow no problems then started to lose power. Got into Cairn lodge services and it gave up. I took the side case off and there was very little oil in the engine.

I believe the gearbox being cooked is a result of there not being any oil in it, but where did it go? I've had this engine for 2 years and covered about 5k miles on it and it hasn't burned any gear oil. Could the rear hub bearing have gone and that has caused friction which has heated up the gearbox which has evaporated the oil?

[johnnyXS]

wow no oil yikes ! sorry for your loss ,thats going sour the Mull experience and be an added expense you wern't expecting

What a mare. My thoughts are that if the oil had leaked and burnt off gradually over the Mull ride you would have heard the noise long before Glasgow or at least some point along the way. You would particularly have heard it when starting up at Mull that morning you broke down.

If there is no evidence of a leak when you do the leakdown then I can only see option 1 really .

1 . Someone drained your oil at Mull !
2. you lost all your oil on the ride there and back .

[a.lo]

Owch! saw the video first and thought it looked very dry in there then saw the rest of the post and realise this is the cause... but how?

[isthmus]

sounds like sabotage

[mark1]

I don't believe for one minute someone has emptied the gearbox. I just can't for the life of me think how it has burned off / evaporated. I should of checked the oil level when we got there. Lesson learned!

I topped it up with about 50ml of oil before we set off. On the way we were on the motorway for the majority of the journey but weren't thrashing the scoots, I never went over 5,500 revs.

Another thing I can't work out is that the clutch plates are ok. I would of thought they would of burned to a crisp but they look fine, apart from being a bit dry lol

Apart from the fact it didn't make it home and I've knackeded some good innocenti parts i'm P~**~@d off because it was running like a dream. Typical I know.

[johnnyXS]

I don't believe for one minute someone has emptied the gearbox. I just can't for the life of me think how it has burned off / evaporated. I should of checked the oil level when we got there. Lesson learned!

I topped it up with about 50ml of oil before we set off. On the way we were on the motorway for the majority of the journey but weren't thrashing the scoots, I never went over 5,500 revs.

Another thing I can't work out is that the clutch plates are ok. I would of thought they would of burned to a crisp but they look fine, apart from being a bit dry lol

Apart from the fact it didn't make it home and I've knackeded some good innocenti parts i'm P~**~@d off because it was running like a dream. Typical I know.

50ml ? thats a spit .... do you really mean 50ml .
I'm sure nobody emptied your oil I just put it up there because it is a possible scenario. When you have eliminated the impossible whatever is left, however inprobable, must be the case

Your scoot would not have run 100's of miles at 5000rpm if the gearbox had no oil. You would have heard screaming squeaking whining sounds and a distinct burning smell would surely have been very noticable.
I'm sure you have been over every inch of the crankcase looking for potential oil leaks. Did you check in the mag and hub housings yet
The engine must have got hot without any oil in the box so Its a pity you didn't do a compression test before stripping as you might find stuck rings and maybe blowby .

[mark1]

I topped the gearbox up with aprox 50ml of oil, I didn't drain it and refill only topped it up.

The top end is still all built up, I'm going to check that at the weekend.

Bearings have arrived today, get the gearbox and layshaft at the weekend. hopefully it'll be built and running by sunday.

I guess i'm going to start carrying a litre of gear oil around with me and check how much is in there at every stop until I get some confidence back

[Wack]

Also fit one of the window level plugs, far easier to just look and see the oil inside.

[Scooterlam]

In the opening post you say you checked and topped up your oil, this would suggest you had lost some oil prior to this trip.
check the usual suspects

[NorthernJordan]

I can't see pictures or the video... But if the damage is as bad as it sounds, I'd imagine you'd have lost some of your oil out of the breather?

[coaster]

Once when filling my gearbox from dry, oil started coming out of the level plug before I'd got anywhere near enough in. Somehow, the oil was running down the internal ribs and running straight out of the level hole I put the plug in and just added the recommended amount in the end.

[johnnyXS]

some very interesting ideas here from Coaster and northern jordan
We are all intrigued to know where the missing oil went Mark .. don't keep us in suspenders ..

Did you get a chance to strip and inspect the engine yet ? was it posibly crankcase pressure ?

[mark1]

All stripped down. The doesn't seem to be any seal failure anywhere.

Rear hub seal intact, chaincase gasket intact and leakdown test shows no leak from the top end.The engine was clean and it doesn't look like any oil has come out of the breather.

I've fitted a new casa rear hub bearing and seal, innocenti layshaft, innocenti LI150 gearbox, new sliding dog and new bearings in the endplate and new bearings for the other end of the gear cluster. Just got to check the shim for clearence them i'll put the clutch in.

I think I'll take Coasters advice and fill up the gearbox in future and not just top it up. I still haven't got a clue where all the oil has gone to though.