How to attach Drive oil pump to lower unit?
 

Hey guys,

I have a bravo 1 lower unit and recently went to change the drive oil but couldn't get the mercury drive oil pump to thread onto the lower unit. My drain plug is behind the prop and I took the prop off but for whatever reason can't get the pump to thread into the hole. Any help or advice would be greatly appreciated.

Thanks,

Seth

Providing the pump is the correct one, it will thread right on. I cant imagine why yours doesnt. Have you compared the threads from the plug you removed from the lower, to the threads on your pump? Can you clean up the threads in the lower and take a close look at them, maybe they are damaged?

My guess is there is simply some debris or corrosion of some type. My Mercruiser pump end is plastic so even if the lower units threads were damaged in some way, I would still be able to thread the plastic end on. If your threads are damaged though, you should fix them while you have all the drive oil out.

What I cant figure out, is Mercury's engineers were brilliant in putting a check valve between the upper and transom assembly, but they have that donkey dick of a drain plug in the lower...

Mine is a pita to get the threads started too, you might have to push on it to get it started. If this is your first time, practice running the plug in a couple of times, its a ton of fun putting it back :lolhit:

The issue is not the threads rather, the location of the drain plug which sits directly underneath the prop shaft. With that being the case there is not enough clearance so that I could get the oil pump connector square to the opening to thread it on. I don't have the drain plug on the side of the lower unit like other models do....major PITA! Talked with some other folks and they said just put a rubber tip on the threaded pump and shove it in there and hold it while someone else pumps in the drive oil, as of now this is the best solution I can come up with....

Thanks for the continued help/advice guys, you rock!

I have a long plastic fitting on My spray bottle. It fits easy.

Seth.. turn the pump end to the left very slowly while squaring it up ever so slightly until you feel it drop into the starter thread. Once you feel it drop in, add some pressure and turn Very slowly to the right being sure to keep it square and level. One thing that seems to help is sitting on your butt instead of squatting down or bending over. The outdrive is at an agnle, your arms ar bent, your back is bent, and the plastic tubing is flexible..that's a complex set of angles and tough to get right with all the variables. Good Luck!

My pump has a 10" hose with fitting on the end, threads right in

You need to take off the zinc anode.

Totally agree with post # 9 or get a slimmer fitting for your pump hose to screw in. Ours just screws in and is thin enough to go inbetween.