G: Gearbox Oil leak

[erik]

The gearbox of my Twin is leaking on the sprocket side. I have fitted a new oilseal and the Surface of the sprocket is perfekt for the oilseal.Any ideas? Erik

 

[rapide049]

Are you sure it is the seal?
Maybe the bottom of the Gear Change cover

 

[erik]

Maybe my dipstick is to short and the gearbox is overfilled?I used a Long cable tie to look how Deep the oil is in the gearbox and it was About 8 cm Deep.Erik

 

[rapide049]

Maybe my dipstick is to short and the gearbox is overfilled?I used a Long cable tie to look how Deep the oil is in the gearbox and it was About 8 cm Deep.Erik

Drain it and measure ,Refill
1 litre

 

[craig]

This is my understanding of Burman grease/oil level.
I am using Castrol 000 grease.

So you look in the fill port and if the grease is touching the bottom of the kick start quadrant, the level is okay.
Yes? No?

 

[Simon Dinsdale]

Craig
Eric states in his first post "the gearbox of my twin".

Simon

 

[craig]

Yes, I see now. I have a mental issues. I own a Vincent.

 

[greg brillus]

The twin gearbox only really needs one litre of oil, the factory specs say 2 pints (1200 ml's) so fill with one litre, then add another 100ml's.......If the oil is just showing on the end of the dip stick with the bike upright on level ground, then that is enough. The leak is probably from between the output shaft bush and the input shaft, common leak if the box oil level is a tad high.......and/or if the output shaft bush is excessively worn.

 

[Vincent Brake]

Or a wobbly seal surface, it will act as a pump than.

Seen a lot of them sprocket's arround.

 

[erik]

On a lathe the seal Surface could be proofed ?Gruss erik

 

[Colin]

Don't rely on your dipstick, they seem to come in a variety of lengths. As advised drain the box then fillup with the correct amount and see where it comes on YOUR dipstick. Then mark that.
In a previous post I had a leak problem finally traced to overfilling and a short dipstick.

There must be a reason why "Dipstick" is a derogatory expression!!

 

[Colin]

See my original post 29th May 2019

 

[erik]

I checked the amount of oil and this was okey.Started to dismount the covers and the Grosset starter Equipment.

 

[rapide049]

I checked the amount of oil and this was okey.Started to dismount the covers and the Grosset starter Equipment.

so what amount did you measure?

 

[erik]

Nearly one Liter.

 

[erik]

The Surface for the sealing is running out of true by two tenth of a Millimeter.