MarkHulme

Hi Guys ,
Upon removing the gearbox on my 2004 Ford Focus Petrol 1.8 in order to replace the clutch , I noticed a quantity of oil drip out of the bottom engine / gearbox joint.
Upon inspection , there was no trace of oil on the clutch , flywheel or the crankshaft seal , yet the side of the engine was wet with oil , not only on the area enclosed by the gearbox , but also right up the whole side of the engine , meaning I have an oil leak somewhere above the gearbox which is running down onto the engine / gearbox joint .
My question is , could this external oil leak have found its way past the joint and into the clutch housing ?
Secondly , Haynes state that part of the seal renewal proceeded involves removing the sump.
I don't doubt that it's necessary , but I was wondering why ?
Many thanks.