Attemping to change the gear oil in a SSM #3 drive......could someone run down the whole process for me.
Do I need special tools?....what weight and brand do I use?....how much oil?.........I hear there''s alot!!

Just drain and start pumping some good ol merc racing lube from a 5 gallon pal.

Just worked on mine today. I use the mercruiser high performance gear lube takes 2.5 gallons per drive. Fill from bottom just like a bravo. Take the big hex plug out of the top back of the drive and fill till oil comes out then put that plug back in next take the upper flat head slotted plug out of the side fill till it comes out there then replace plug. Next go inside bilge to transom assembly remove plug then fill drive till you see oil just in the bottom of the reservoir. If you have extra expansion bottles you can fill to the line in the sight glass but without expansion bottles oil will blow out the vent all over your bilge. I learned the hard way what happens when you don't get these drives filled rite lol.

I use Amsoil 75w-140 severe gear in mine. 2.5 gal is correct, I generally fill mine thru the large hex nut for the bulk of it then pump the rest in from the bottom until I get a level in the expansion tank.

Wow...2.5 gals apiece!...........guess I'll need a very large container to hold all the old oil. How do you remove the plug from the lower case (bullet)
and is it magnetised to catch metal shaving?

flat screwdriver and yes my lower plugs have a magnet

I would run the 75w140 as well.

I have been running mystik 85w140 gear oil in my SSM #4's for a couple seasons now. When I switched to it, the metal fuzz on the magnets decreased to nearly nothing, compared to the 75w90 i was running. Had drive torn down this winter as I had a bad prop seal letting some water in. Gears still looked great. They sell the mystik at farm and fleet for 65 bucks for a 5 gallon pail.

Biggest problem with those drives, is keeping an eye on the fluid. If you get water in them, or lose oil, they obviously will get hurt. Other than that, they are very reliable drives and can take some abuse.

Is Mystik a synthetic oil?...................are you recommending 75w140 -or- 85w140 for the SSM 3's ?

75weight versus 85weight?

That`s your question?

Pretty Inconsequential.

Yea, that's my question and who would really care or have the balls to nit pick like you!..........your not amusing. What you are is rude & condescending.....really Bro, give up the mocking thing!