Hi Craig, from the photos your inner drive shaft boots don't seem to be sealing onto the drive shaft well, if this is the case you need to replace them. This is best done with the gearbox out as the drive shaft allows access to the boots. Obtain a Haynes manual for the 500 and tackle the job in line with the book. I would change ALL seals on the drive shafts at the same time (inner and outer)
Hi Craig, regarding the diff drip, try to determine the actual oil there - gearbox or engine? Oil can get everywhere with these cars so best be sure of the origin. The drip could just be running down the casing from the driveshaft boot area and if in doubt clean both sides carefully and take a long run then leave the car to stand and cool for a while then check for drips. Remember these cars are largely not oil tight unless you are lucky be prepared for oil loss anywhere at any time!!!!!
With regard to gaskets; there is no gasket between the bell-housing and the main gear-box 'body'---just a metal-to-metal fit with a smear of sealant on the surfaces. As well as the seal in the drive-shaft boot, there is also an 'O' ring seal between the gear-box and the bearing-holders. There is a seal where the gear-rod comes out of the front of the gear-box and a bearing-and-seal in the bell-housing where the spigot-shaft comes into the bell-housing. This bearing+seal comes in a small housing---much easier if you buy the bearing/seal/housing as a (small) complete unit. However, Ian's suggestion that you clean all the oil off, and then check it after a run is a sound one.
Discovered the same issue with the left side drive shaft boot in mine as well. Looks like I'll be pulling that shaft and replacing the boot. Probably have to do both as well just to be safe. Thanks for the tip!
