Thanks for all the past help. I have an 86merc xr2 150HP that starting leaking gear oil out of a teardrop shaped hole on starboard side of lower unit. I recently hit 2 stumps at idle speed while on a fishing trip. I'm sure that has something to do with it. I will be dropping lower unit today. From other posts I see to pressure test to determine location of leak. Can someone explain that procedure to me and what to look for.