Impeller/Outdrive Oil Service?
 

I usually bring my boat into town once a year for outdrive service. I hate towing it and it sits on a lift full time. This year I want to change the impeller and think I could do both services myself. I have just enough knowledge and tools to be dangerous. Should I attempt this or take it to a boat shop and forget about it. Does Mercury have a step by step manual or is there a good site to check out? I remember reading about a bug type sprayer to put the lube back in, what type of fittings are needed? Any help is appreciated. The combo is a 502/Bravo 1 Thanks

The fluid is no problem, but you need to rig up a oil pan or something that can stay there a while. Better yet run the boat to heat up the fluid, put it on the lift then drain. You need to remove the prop first then there is a drain plug at the bottom behind the prop. Take it out then crack open the vent plug (Same looking thing) on the right side near the top. Make sure you have a oil pan that will take at least 4 quarts. If cold I let it drain overnite. I keep the drive down and level. To put the fluid back in get a pump from any merc dealer and follow the directions, It is like a soap pump bottle with clear hose. you screw it on to the top of the bottle an pump away. Usually 3 - 4 quarts. I leave the vent plug off until the fluid starts appearing at the hole then plug. Keep pumping about another quart and watch the resivour tank, Stop pumping about 1" below the line, It seems to keep expanding for a minute or two.

The impeller is on the bottom left of the engine (usually) and it is a belt driven pump. It would be easier for you to remove the whole pump then replace the impeller on a bench, Or if you want take it to a merc dealer and let them do it. It is pretty easy though. Removing it is the hard part. I am assuming you have a Merc big block,, right??

Just changing the gear lube is a pretty simple procedure as Raypanic explained. Another important aspect of an "Outdrive Service" that you would get at a merc shop would include removing the drive so the engine alignment could be checked. If you alignment is not right and your coupler goes out it will cost $$$$$$. Outdrive services are not very expensive.

One more thing, you might try Red Line Shockproof oil. We have had great success with this. Smoother shifts, cooler temps, more.

I am having a coupler replaced because of misalignment, $350 just for the part. Fortunately the motors are out of the boat so no additional cost.

I'm going to be changing the outdrive oil on my Baja .38 Special here shortly. Can anyone explain why the fluid needs to be pumped back in through the drain hole? I was thinking I could just pour it into the bottle in the engine bay until fluid starts coming out of the vent hole. Then plug it and finish filling the bottle.

Also, what is this "coupler" exactly, and how does the outdrive come out of alignment in order to damage it.

Bubbles and air pockets M1super90. The only way to assure NOT to have them is fill from bottom up. Remember to take off your drive bottle cap as you pump upward.

Sydwayz is correct. You must push the air up through the top vent hole to get all of the air out. The coupler is bolted onto the flywheel to transfer the power from the engine to the outdrive. The outdrive input shaft goes into the coupler and if the alignment is off the coupler splines will strip. The coupler is mounted in rubber to help absorb vibration.