SEI lower unit for 120 FORCE

[adrian Martinez]

Hi there, i've purchase a lower unit from you guys for a 1996 120 FORCE BY MERCURY MARINE serial #OE 197954 and when i placed the order i was told that i had to replace the shift shaft be cause it will not work without it ,i still did not buy it be cause judging by the instructions ,that piece will not fit my engine,plus that engine on the instructions on line does not look like my set up at all i was very worried for a whole week till the unit arrived last tuesday , I opened and install it put oil and... everything worked perfect ,long story short I'm glad i did not order the shift shaft kit and remove the power head while i was waiting for the unit to arrive,this lower unit is a direct fit for my engine no mods needed .:)

thanks.

[admin]

Do you know if you have a 3 jaw or a 6 jaw reverse clutch on your original unit? If it is a 3 jaw, the unit will fail. You can bolt a 6 jaw unit where a 3 jaw was, but the amount of shift throw is different between the two. That is why the shift shaft kit is required for units that are 3 jaw. I would suggest verifying that your old unit is indeed a 6 jaw. If it is not, then you need to purchase the shift shaft kit and install it before running the new lower unit. I can't tell the year from the serial number, but some data i found suggests if it is a 1987 to 1997, it is a 3 jaw and would need the shift shaft changed. If it is 1998 or newer, It will be a 6 jaw. If it is a 1997 or 1998 I would pull it apart to verify. Model years don't always match up with calender years.

Tech Support

[adrian Martinez]

1996 120 force

Hi there ,shut!! but how come it shift so normal no different from my previous lower unit? i did tested it on my driveway with the headphones and the hose and runs pretty normal to me ,before i installed the unit i turn the little knob while turning the propeller shaft and seems that all it needs is like a 1/4 of an inch rotation to engage ,and thats what my shifter throws please let me know what coud fail if i tested my boat carefully in the lake (i always carry my kick motor any ways just in case) thanks.

[admin]

I emailed you an image to your hotmail account showing how to identify a 3 jaw vs a 6 jaw. If your old unit looks like design 2 then you are fine. If it looks like design 1 then do not run it until you change the shift shaft. It will seem to work okay, but you will not be fully engaged in the clutch and it will break. Let me know what you find.

Tech Support

[adrian Martinez]

thanks , i have a 3 jaw ,at list i know what the problem will be now thanks and i will order the part