did you put any sealer on the pinion and flange splines before fitting the pinion nut? i've had oil 'wick' up the splines and leak round the nut before so i always seal the splines now.
neil.
Last night I while turning into a gas station the rear end sounded like it exploded. I guess after ignoring the leak for months finally the gear oil was finally too low. I drove it home like that without issues or noise. So today I took the pinion flange off to replace the seal. It hasn't been that long that I replaced the seal and it appeared to be in good shape when I remembered the above comment. I decided not to replace the seal and just put some pipe dope on the splines. I didn't drain the gear oil, so it kept dripping out, but I was able to clean the splines good enough. I still had just enough Lucas 80w-90 to fill it up.