Oil seems to be migrating from gearbox to engine of my Rapide. After 14 years this is the first hiccough since a rebuild and constant use (albeit not a massive mileage). Also, the oil remaing in the gearbox is quite discoloured after a relatively low mileage. New seals are in the process of being fitted and except for PD26 they were in OK condition. PD21 had marks that indicated a less than perfect fit in G24 but nothing catastrophic. None of this seems to explain the badly discoloured gearbox oil. Suggestion please.