Just slid under the rear of the 91 240, and noticed oil on the rear differential. Not a lot, but just enough to make the dirt shiny. No drips on the driveway - yet. Wiped the oil and dirt off.....this is a southern car - no rust on the car at all - differential paint is still clean underneath. The car does not have ABS.

The differential plugs are tight. Looks like it may be coming from above and to the left of the fill plug when viewed from the rear, where the speedometer sensor goes into the differential.

Is there an easy way to seal this thing? Bentley references a "lead seal" (?). Does the sensor cap unscrew, or just push in? It looks like a metal cap, 1.5" or so in diameter, and 1/4" high. Will RTV work as a sealer?

Thanks. Also curious if we should drive the car. The leak is minimal at this point.

Thanks.

Dave
91 240