Eric; The procedure for replaceing the oil seals is to; Undo the coupling, pull the trans, remove the bellhousing,(after blocking up the engine, the mounts are on the bell housing) pull the flywheel, (after removeing the starter), remove the adapter plate. This gains you access to the crankshaft oil seals. They are in two halves of a casting bolted to the rear of the engine going around the crankshaft, I have replaced them twice since I didn't do it right the first time. The seals look like packing for the shaftlog. several tricks I have learned are; soak the seals in oil 24 to 48 hours befor you install them , they will glaze over before the oil reaches them if you put them in dry. There is a graphite compound you can also use but still soak them first. Also use a joint compound on the gaskets to eliminate future leaks ( seepage ). I took a 2 X 4 about 12inches long and cut it on the diagonal to make two wedges, then pound them together under the oil pan to raise the rear mounts off their seats to facilitate removal of the bell housing. I also took a small pattern file and removed the high areas on all the holes in the various parts so they would fit back together better, all British engines seep oil due to the poor mating surfaces. Xanadu is a 1984 384 with a 4000 RPM "New" 4-108 Perkins. Good luck , if I can be of further help send me an e-mail, I live aboard and don't always get mail promptly but I will Get back to you.