RonLee wrote:

My tach cable housing (Lycoming) leaks nasty black stuff so I cleaned
and dried it. What is the best lubricant to use? Particularly one that
does not deteriorate and leak through the housing. What about a
covering for the housing to prevent the leaking?

Lube the cable with wheelbearing grease and if there are any cracks in the
plastic cover on the cable housing, you can recover it with heat shrink
tubing for about 2 bucks. I do this on motorcycle cables all the time.

Tony