Early Tach Drive Pumping Oil

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Oct 28, 2009
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I have a 1968 Commando with the tach drive on the timing chest cover (right side). Oil seems to pump through the tach drive, and out the connection to the tach cable. Has anybody come up with an oil tight connection between the tach drive and the cable? I tried putting an o-ring sandwiched between the cable and the drive, with no luck. Anything else? Just to be clear, the leak takes place where the lower end of the tach cable attaches to the tach drive, so I don't think the traditional tach drive mod will help.

Stephen Hill

1968 Fastback
1970 Mercury
1971 Roadster
1974 Interstate
No experience with what follows, but I've heard that you can take one of those little conical seals that seals the oil pump to the timing cover and use it, beveled side in, on the tach drive with good results.

I probably heard that on this board, so perhaps whoever originally promulgated the thought can chime in?
Are you sure it's not oil from the cable itself? It's a pretty tortuous (sp??) path from the timing chest past two gears and up to the cable. I packed mine with bicycle grease and when I was a kid I used wheel bearing grease, never had a leak there. BTW, a slightly filed nickel makes a nice plug for the speedo drive, and one from the year of your bike gives it a distinctive look.

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