Gearbox oil leaking

fritz

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I will be investigating, but to maybe speed things up....

I've noticed I have noice green lubricant running down back plate of gearbox, appears to be coming from top of box where airbox assembly mounts.

I'm guessing perhaps the little retaining nut for the airbox cover has come undone of something similar.

If not, any other thoughts?

I seem to recall that there is a breather in there (not engine one into carb inlets) or maybe I'm confusding the one on speedo drive.

Anyway I will have to take carbs and whatnot off - but any clues and anything else it might be could save me some time.

I put a rebuilt box on around 6,000 miles ago - hence thought maybe nuts come lose on top.

Many thanks Fritz :thumb
 
I suppose the first question has to be - "What is the green lubricant ?"

Is your engine oil green (as in Halfords Classic 20W50) or is the gearbox oil green (I've never seen green EP90 :nenau).

The Airbox has an engine breather in it - with pipes leading down the air ducts heading for the carbs (don't get Proff started :blast). The oil from the breather shouldn't get into the airbox unless the various plastic pipes and rubber junctions have come apart.

The bottom mounting bolt in the airbox bolts to the top of the gearbox. This hole is open into the box so if the bolt has come out I suppose gearbox oil will get into the airbox. There is a 'duck bill' drain at the rear of the airbox that will let fluid out (down the back) but not in (i.e. when wading).

I suggest you thoroughly clean the whole area and then have a good look at where the 'lubricant' is coming from - both where it originates and where it is escaping.

Then let us know.

I wouldn't start taking anything apart just yet.

Bob.
 
leak

dont dismantle anything until you have checked the oil pressure switch which if knackered can leak through the plastic centre
 
oil (gearbox - engine oil too old to be as green as it is, hence not from engine breather either) is coming out from back of airbox on top of gearbox - I cleaned it all off before having a test run.

I'll keep you informed, I guess it's the pesky bolt that needs the most stuff taking off to get too :augie the one that holds airbox assembly to gearbox.
 
I guess it's the pesky bolt that needs the most stuff taking off to get too :augie the one that holds airbox assembly to gearbox.

Its the easy one of the three, having a hex head and being easily accessible once the airbox cover and filter element have been removed.

Hopefully the setscrew will still be in the airbox, not somewhere down in a carburettor :eek:

I hope you haven't been "ear 'oling" it recently :D :D

Keep us informed :thumb


Bob.
 
Solved

2 things I have mainly learnt today:-

Trust your judgement and don't overlook the obvious!

What looked like a leaking end case gasket indeed was.
No nut loose in airbox, the oil just happened to be flowing top top centre down more obviously.


The screws holding the end cover on were all loose...to point of a couple being finger (loose) tight.


Those nuts are only about 8Nm anyway. I'm guessing the gearbox was assembled but the nuts never given their final tighten...think we've all done that in the past on some rebuild. Anyway easily resolved - and grateful I noticed it here rather than on one of last years high mileage legs. I'm just grateful to not be taking it out and returning, much better this way.

Funnily enough when checking it after tightening bolts I noticed oil dripping from oil filter casing...I'd resisted overtightening those myself and they just needed a small nip too.

Amazing how these showed up after a few months inactivey rather than when riding to the Ukraine and back.

I'm not complaining!

Lessons learnt - the obvious leak (that I figured was too simple) was the obvious issue and a quick test with an allen-key would have confirmed it straight away first time.

Fritz ;-)
 


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