by George Lyle
What I do is put grease onto the cable generously as I feed it into the tube. This works for all cables (clutch, speedo, etc.) that go into a tube or sheath.
If the cable cannot be removed (or I'm too lazy to do so), I mix gasoline and bearing grease to give the grease a "pourable, thick" consistancy. This will work its way into cables, then the gasoline will evaporate leaving the grease. This stuff also works for lubing noisy speedometers, but you have to fabricate some sort of "funnel" to guide the gas/grease to where it is needed.
For cables, you can also use motorcycle chain lube, which comes in an aerosol can. This stuff is a _sticky_ grease in a solvent carrier If you seal the end of the tube to the little tube from the chain lube can, you can pressure-feed lube through the tube. Messy, but it works!
Unless you live in the Arctic, avoid light oils and WD-40. They don't
last all that long.