25 hp lower unit

I have a 1990 25 hp Merc that I took in this past spring to a very reputable dealer to have the water pump and lower seals replaced. I was getting discoloration of the lower gear oil (milky). Had the work performed took it out on the water, came home and checked the lower oil, it was ok. I replaced the gasket on the drain plug tightened it and ran it through the season giving it no thought.

Well, I drained the gear oil to winterize and guess what..... it was milky. I have double checked the invoice and part numbers and compared that to a parts diagram and at least I was charged for all the right seals and parts. What do you guys think....

Did they botch the job? Did they not do it and just charge me? Or do I have some sort of more serious problem (which I have no idea what that could be).

I am mechanically inclined. I did replace the drain plug gasket and made sure it was tight when I checked it just after the service. I removed the prop to look for fishing line and found none. I might add that when I originally took the motor in for service I could run the motor in a 55 gal drum all day (lower rpms) and the gear oil would not get contaminated. It was only after I took it out on the water and ran it wide open that when you returned home and checked the gear oil it was milky.

Any ideas?

Re: 25 hp lower unit

First you need to figure out where it leaks.It's possible one of the seals failed.
It's possible one of the shafts wore down and let water in.
Find where it's leaking.
It's possible it won't leak on a pressure test so get someone to do a vacume test too.J