Diff leak:
http://forums.corvetteforum.com/c5-t...ing-fluid.html
Just to let you know, oil can also come out of the differential's vent located at the top/drivers side of the differential. Once and awhile on my Zee, I would notice oil on the floor dripping off of the driver's side of the differential cover ... but if I wiped my finger around the LH seal it was dry.
So I thought it might be the LH cover O-ring (also a common problem). I also found oil residue up near the vent ... and ultimately concluded that the venting oil would run down the gap between the LH side cover and the differential body and drip off the bottom of the LH cover.
It can be very deceiving on where the oil is actually coming from, and suggest you determine exactly where it's coming from before going in for a repair that might not be required.
GM TSB:
Recommendation/Instructions:
When installing the rear axle side cover(s) a new o-ring and axle seal should be installed and a material such as LoctiteŽ 518 should be applied to the outboard side of the o-ring. The sealant should be allowed to set prior to filling the axle with oil and driving.
Part Numbers (Correct as of 9/2/03)
Side Cover O-Ring Seal - 89047953
Axle Seal - 88996703