If the oil was ONLY at the bottom of the bell housing good chance it's a rear main.You only need to understand gravity, trace the leak to the highest point and start repair there. I've had too many bad experiences with incompetent techs guessing the source of oil leaks. Customer returns still leaking, I made the tech repair at no charge. I would not quote an oil leak without cleaning the engine and using a tracer dye first.

 

yes you can pop off the cap on the bell housing with a flat screwdriver.

 

Degrease the bottom and side of the engine and wipe clean. This will be a very dirty job but you will have satisfaction at the end when all is shiny clean. I would also take the skid plate off if you can. I had very bad oil leaks and in some places there was an inch of build up of oil and dirt and sand.

I would also check to make sure all bolts are tight and nothing is loose, like the oil pan, oil filter, check the oil cooler lines next the the oil filter, it’s going to be a little labor intensive.