I did this job a few years ago. It's a PITA and does require half the car to come apart. IIRC I had the same problem and it took me going over the pan several times and reviewing the Bentleys a couple of times before I found the bolt I missed. It was at the rear by the bell housing. I think there's one back there that is kind of concealed unless you look at it the right way. You'll find it. The job sucks but its very satisfying once its done and there's no more leaks. While you have things apart replace the seals at the front diff and axle carrier.