the speedo cable should have a rubber seal at the bottom in the box on the very end of the cable..also should be another at the top where it goes into the speedo head...if these o ring seals are broken/not there you will get oil travelling up the cable and then drip on your legs/feet....seen it plenty of times...easier to change the speedo cable which would be $25 for a second hand one or around $75 new..i am presuming its just a trimatic/aussie 3 or 4speed?...same cable.