Like I originally said, and as the shop said, looks like the main seal. By all means have another shop look at it, but I'd be really surprised if it's something else.
98.5 SVT
91 Escort GT (almost sold)
96 ATX Zetec (i brake to watch you swerve)
FS: SVT rear sway bar
WTB: Very cheap beater
CEG Dragon Run - October 13-15