GB Gearbox Oil Leak

[nevhunter]

I am here to support the idea of spiral grooves. They WILL move oil in a particular direction when you are running. I've used the technique often in various places in gearboxes where there is no room for an oil seal. You can even us it on a thrust face, with a spiral groove. Has to be in the appropriate direction of course and it doesn't have to be very deep to work. Nev

[jj.palmer]

Hi
Same as yourself Nev I've been associated with the use of spiral grooves particularly years ago in the design of drilling jigs where the cutting fluid had to be pumped, via a spiral groove, to the cutting tool edge.
The problem I believe with the speedo drive is whilst it is rotating it acts as an effective oil seal but when you come to a stop the residual oil in the spiral groove runs out and down the cable. After 150 miles of running I can only detect the smallest amount of oil in the "oil soak pad" indicating it is only the residual oil that is leaking.

Regards
John Palmer.

[adrie.degraaff]

Dus anyone thought of the fact that the oil is suppose to run in to the cable to prevent it from breaking, if it was running dry and there came a crack and there for water in the outer liner it would rust and break.
So the best idear on this topic is shrinking an extra liner around it for the first 50 cm.

[jj.palmer]

Hi
Taking your comments Adrie I totally agree with you that the inner rotating gable must be lubricated, which it is, and that heatshrink should be fitted over the outer cable, which it is. My problem, like others looking at the posts made, is that oil leaks from the threaded connection between the cable and the gearbox. I'm quite happy at the moment with what I've done, to catch the oil, until someone comes up with a more positive solution.

Regards
John Palmer

[PeterW]

Nice practical solution with the benefit of supplying ready-to-go oily rags :¬)

[Bob.Murphy]

I used to leave the knurled nut at the speedometer loose. The oil would then climb the inside of the cable and run down the outside without getting into the speedo.

I used to wipe the oily flies off the cable after each run .

I never had a cable seize .

Bob.

[nevhunter]

Many speedo cables don't connect direct to gearboxes. It's often driven from one wheel. Grease during assembly of the cable does the job OK for years and you certainly wouldn't want an excess of oil around that might just get into the speedo. These days an oil leak is a problem legally, more in some places than others. Nev

[tonyh]

I posted about this dribble some time ago and gave up after trying all the suggested mods. I think the nappy thing is worth a try. I also agree with Nev as I have a few old clangers with front and rear wheel drive cables which run for years with no problems and little lube.
Tony

[jj.palmer]

I realise that this is an old posting but the problem of oil leaking out of the speedo drive and cable still persisted but fingers crossed it is now cured, although it did take a little time.
Has suggested I used heatshrink tubing around the cable and made a new "washer type circlip" for the gearbox drive, see attached sketch, which hopefully is self explanatory.
When crimping the "washer type circlip" it tended to bend, so I therefore crimped it a small amount and then flattened it with the tool shown, this process was repeated until it was crimped sufficiently.
I also put rubber tubing around the heatshrink at various points to protect it from being damaged by the frame and the hot exhaust pipe, see pics.

Regards,
John P.

[Ian.Taylor]

I ended up using the small washer used on the primary case screw. I just put it over the drive end. Cut down the leak dramatically!