Oil dripping from speedo cable

[PaulR]

My first post ... so here goes.
Having spent a good few months successfully fettling most things on my 57 VH500, I'm now going back over what I thought I'd sorted out but plainly haven't !!
I replaced all the gaskets and seals throughout the gearbox, including the 'o' ring on the speedo drive bush. All the gasket mating surfaces were cleaned up and various threads saved.
It took a while to figure out where the oil was coming from until I was sure it was not coming from the sump plate and/or the cam cover gasket, but oil was dripping from the lowest point of the cable.
I thought about changing the cable, or sealing the existing one with heat shrink, but I'm not so sure a speedometer cable is supposed to run in oil if at all.
Have I missed something say between the worm gear and bush at their point of contact in the gearbox ? is this a common/uncommon problem ?
PaulR

[dave.owen]

Common problem of oil exiting gearbox via the speedo cable

[Roger Gwynn]

The oil is mainly prevented from leaving by a spiral groove in the spindle, which as it rotates returns the oil to the gearbox. No problem when in daily or weekly use.... A small fibre washer under the thing that goes between the speedo cable and the bush does reduce the drip.

[JohnnyBeckett]

Hi Paul welcome to the Ariel forum, i put thick high melting point grease on the speedo shaft before i fit it all together and with a fiber washer like Roger says and now it doesn't drip oil

[PaulR]

Thank you gentlemen that know ... is it possible to remove speedo drive bush and shaft without removing g/box cover ?? would save a fair bit of time .... otherwise, off it comes again !

[Paul Slootheer]

As Dave said, a common problem. Most, if not all, makes of British motorcycles on which the the speedo drive comes from the underside of the gearbox suffer from this problem. If it leaks on the cable joint (from alluminium to plastic coating) you can cure this problem by fitting a piece of heath shrink hose. Make sure it starts on the aluminium and ends on the black outer plastic coating of the cable. This worked well on my 1954 NH…

[jj.palmer]

I had a similar problem, I found that one oil leak was due to the "split circlip" that holds the drive connector to the gear box drive, the oil leaks via the split in the circlip, I fixed the problem by making and fitting a non split circlip that had full sealing faces.
The other leak was via the damaged outer cover of the speedo cable, this I cured by fitting heat shrink,.

See attached sketches.

Hope this helps,
John P.

[JohnnyBeckett]

hi Paul you can remove speedo drive by removing the grub screw holding it in and pull out the complete speedo drive out the gearbox

[dennis.t]

I put a small O ring behind the flared section of the speedo cable where the nut screws onto the gearbox and packed the joint with heavy grease. This has slowed the oil leak considerably.
Dennis