G: Gearbox (Twin) Twin oil leak(s)

Colin

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My Egli Godet Sport GT has been suffering from a persistent oil leak that I have been unable to trace for some time. Even when the bike had stood for a while it continued to drip a little, despite all efforts to seal joints etc. Today, after checking "the books" I decided to drain the gearbox oil and measure the amount. There was quite a lot of soft gunge adhering to the drain plug, but the oil looked clean enough. However I drained 1.3 litres of oil! Depending on which book you read the recommended amount is 2 pints or 1litre. Since 2 pints is a little less than 1 litre clearly 1.3 litres was too much. So I refilled with one litre of a green 20/50 mineral oil. Hope fully if it continued to leak the green would show up. ( my engine oil is brown) After it had all settled I checked oil level against the mark on the dipstick. The oil was just, and only just, showing on the dipstick, nearly half an inch below the mark on the stick. Obviously what has happened is that the dipstick was marked and inserted and then someone filled the oil up to the mark, WHICH WAS IN THE WRONG PLACE. I made a new mark on the dipstick (and a note in the file about the correct mark). I then went for a 40 mile ride, giving it a thrashing through the gears , and parked it over a carefully placed, clean plastic sheet.. It has only been about 5 hours since the end of the ride but although there is the odd drip (of indeterminate colour) there is very substantially less loss than before,.OK by me. Since twin gearboxes do not, apparently, need regular draining, YOUR box MAY have too much or too little oil. It is simple enough to drain and check, maybe it's an idea to measure/change gearbox oil a little more often, what do you think?
 

Garth Robinson

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My Egli Godet Sport GT has been suffering from a persistent oil leak that I have been unable to trace for some time. Even when the bike had stood for a while it continued to drip a little, despite all efforts to seal joints etc. Today, after checking "the books" I decided to drain the gearbox oil and measure the amount. There was quite a lot of soft gunge adhering to the drain plug, but the oil looked clean enough. However I drained 1.3 litres of oil! Depending on which book you read the recommended amount is 2 pints or 1litre. Since 2 pints is a little less than 1 litre clearly 1.3 litres was too much. So I refilled with one litre of a green 20/50 mineral oil. Hope fully if it continued to leak the green would show up. ( my engine oil is brown) After it had all settled I checked oil level against the mark on the dipstick. The oil was just, and only just, showing on the dipstick, nearly half an inch below the mark on the stick. Obviously what has happened is that the dipstick was marked and inserted and then someone filled the oil up to the mark, WHICH WAS IN THE WRONG PLACE. I made a new mark on the dipstick (and a note in the file about the correct mark). I then went for a 40 mile ride, giving it a thrashing through the gears , and parked it over a carefully placed, clean plastic sheet.. It has only been about 5 hours since the end of the ride but although there is the odd drip (of indeterminate colour) there is very substantially less loss than before,.OK by me. Since twin gearboxes do not, apparently, need regular draining, YOUR box MAY have too much or too little oil. It is simple enough to drain and check, maybe it's an idea to measure/change gearbox oil a little more often, what do you think?
I think it is mentioned somewhere in Richardsons book to fill the gearbox only to the bottom of the dipstick,not to the flat bit further up.
 

greg brillus

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Actually a pint is 600 ml's, so 2 pints is 1200 ml's. The boxes don't need anymore than 1000 ml's to function correctly and I prefer to use a 80w 90 gear oil rather than engine oil. The thicker oil is less likely to leak, and the reason they do leak if filled more than necessary is that it bleeds out between the output shaft bushes which have no seal.
 

BigEd

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Well ---------- not all of them have no seal
I knocked the G17 bush a little further into the G4 and pushed an ET104 pushrod tube gland into the space created. You can do this without taking the gearbox to bits but you do need to take off the G1 kickstart cover and dive in. You can carefully slide the ET104 along the shaft. An oily plastic bag put over the shaft first makes this easier.
 

Colin

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This is getting to be an interesting can of worms. You are of course quite right Greg that two pints are more than one litre, and I should have looked at my measuring jug more carefully. This may well account for the phraseology in the Riders Handbook " The box holds NEARLY two pints of oil" (not exactly a precise figure is it). Looking at my measuring jug again, I see that one-and-threequarters pints is pretty near, even quite blooming close, or as near as dammit' one litre! As I spilled a bit of the oil when filling with one litre, I have undoubtedly now got nearly two pints of oil in the box, and it is clearly this level of adherence to the technical data that has ensured that it doesn't seem to leak now (or if you insist on precision ) not nearly as much as before.!
However in deference to any Very Old Child, who may have the temerity to follow the Egli on any spirited riding around the Ardennes in the coming few days, my advice would be "Hang back a bit Mate, it just might be a bit slippy along here! Don't say I didn't warn you!!
 

Colin

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My Richardson says (in relation to the dipstick) "gives a reading to the underside of the dipstick flat" Ah, yes , well , as it happens my dipstick doesn't have a flat, just a small groove (as we now know--- in the wrong place) but hey ho it seems that providing we have, "nearly" two pints or "approximately" one litre of either engine oil (green being my preferred colour---but please yourself) OF COURSE if you are "down under" use 80/90 gear oil. Think about it, down under, oil us bound to flow to the top of the gearbox which is of course upside down when you are down under. Simples!
PS As a matter of interest why do meercats, who inhabit Africa, speak with a Russian accent?!
 

Pete Appleton

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Ah, but is the capacity for Godet cases the same as for Stevenage ones?

I would rather have a leak and know that there is enough in there.
 

Simon Dinsdale

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Just to add to the complications, I have seen different length gearbox dipsticks. My Rapide has never leaked down the mainshaft as I keep the oil just touching the end of the dipstick. When I got my Shadow on the road I did the same but it leaked down the mainshaft. Eventually I compared dipstick lengths and found the Shadow one shorter by 1/4". Once corrected and oil lever set to same as the Rapide, the Shadow's gearbox stopped leaking down the mainshaft. So the level appears to be quite sensitive if 1/4" difference is all it takes.
 
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