crankshaft oil seals modern design

Checking a crankcase side-cover gasket
On some engines — such as those fitted to certain Leyland cars — there is a cover over the camshaft tappet chamber on the side of the crankcase about halfway down the engine.
Oil under the clutch housing may come from the crankshaft oil seals.

The cover is hidden by the inlet or exhaust manifold, so leaks from its gasket may be hard to spot.
With the engine running, look for oil coming from the lower edge of the cover. You may need a small mirror and a torch to see.
Tightening the cover securing screws slightly may cure the leak. If not, replace the gasket.crankshaft oil seals modern design