Lower unit oil top 2 plug

[San Chan]

Did some searching on a few Forums and found info that I didn't do when winterizing.
Am I supposed to have both unscrew and fill it up till one overflow and than plug it......fill it more till 2nd one overflow......... When winterizing mine I only did one top hole till it overflow and unit took about 600ml. Do I have to do it again when Spring comes?

[Hot Runr Guy]

If your lower unit is similiar to my 75 Opti's, you may have over-filled it. The procedure is to remove both upper screws, fill from the bottom until the lube appears at the first one, then install both upper screws before removing the filler from the lower (fill) location. In the spring, with the motor level, remove the top (vent) screw first, then the other, upper screw, and let the excess drain out. If you need a copy of the service manual page I have, let me know, and I'll scan and post it here for you.
HRG

[fxnrxn]

I guess it depends on your motor. My '03 Mercury states in the manual to fill with lube until it seeps out the front vent, then put the plug in and continue to fill until it seeps out the rear vent hole, then plug the bottom.
Mike

[San Chan]

If your lower unit is similiar to my 75 Opti's, you may have over-filled it. The procedure is to remove both upper screws, fill from the bottom until the lube appears at the first one, then install both upper screws before removing the filler from the lower (fill) location. In the spring, with the motor level, remove the top (vent) screw first, then the other, upper screw, and let the excess drain out. If you need a copy of the service manual page I have, let me know, and I'll scan and post it here for you.
HRG




If you don't mind posting it, that would be great. Thank you

[Hot Runr Guy]

Here you go:

[San Chan]

Here you go:




According to what you have there, the step I am missing is not having 2 top screws removed when refilling. Can I remove them both in the spring and fill up again since I only have one top vent unscrewed. All I am worry about is not having enough oil in there. Or maybe drain it totally and redo it all over.
Anyone?

[Hot Runr Guy]

San Chan,
Mercury has changed the re-filling procedure. The one I posted above is from a "printed 2003" service manual, my 2008 owners manual indicates to fill until fluid comes out of the forward(lower) hole, then continue filling until it appears at the rear (upper) hole. Check your owners manual for the proper procedure. If your manual says to fill until reaching the forward (lower) hole first, then the other, in the spring I'd pull the drain plug, stick the filler in there, then remove both upper screws, and finish the procedure.
HRG

[San Chan]

San Chan,
Mercury has changed the re-filling procedure. The one I posted above is from a "printed 2003" service manual, my 2008 owners manual indicates to fill until fluid comes out of the forward(lower) hole, then continue filling until it appears at the rear (upper) hole. Check your owners manual for the proper procedure. If your manual says to fill until reaching the forward (lower) hole first, then the other, in the spring I'd pull the drain plug, stick the filler in there, then remove both upper screws, and finish the procedure.
HRG



Thank you, I will check that