Almost milky oil in upper gear case

[OMC73]

Just got done with my impeller replacement and tested it out this evening. It seems to be working great! What a freekin relief! Lol. Anyway, I changed out my lubes before my test run. I checked the upper after running the engine about 5 minutes. The oil wasn't completely milky but it looked like it was beginning to get that way. So my questions are, is it okay to run it this way​ and change out the oil every few times of taking it out? And, how involved is the reseal job? I have a manual but it helps me to read real world experience.

Thanks!

 

[Scott Danforth]

Drain the gearbox and pressure test.

Two common leak points on a stringer upper are the waterpump housing and the vertical driveshaft or the ball gear input shaft seal