1991 Force 70 HP lower unit oil change

[Chris73Cobia]

I'm trying to change my lower unit oil, as I don't want to go more than 2 seasons w/o doing that. I have the knowledge of which plugs, and how to fill it up, that's the easy part. Getting the darn plugs out is the hard part. It seems even with my biggest screwdriver it just kinda pops out because the slot is so wide. I can't find any screw driver with a wide enough blade to grab the whole plug, and I don't see any "thick" enough to fill into the whole slot to prevent it from slipping out either.

I'm sure I'm not the first to run into this problem, hoping it's not a "take it to the boat shop" issue.

Thanks in advance for the advice

 

[Frank Acampora]

Re: 1991 Force 70 HP lower unit oil change

Go to Sears and buy an impact screwdriver. Use the large flat tip. It will take them right out. It doesn't skip out of the slot because the force of the hammer blow pushes the tip down into the slot while the internal cam increases the twisting force. Do not get too enthusiastic when tightening them because with this tool you will be able to strip the threads.

Alternatively, if you like doing things the hard way, buy a bigger screwdriver. They do make them big enough to fit the slot and can be found in almost any tool seller.

Got an old chewed-up screwdriver? Grind the tip back until it is thick enough to fit the slot. A square shank is best because you can put a small open end wrench on it to increase leverage.

There's three ideas for you but the impact driver is the best.

 

[Chris73Cobia]

Re: 1991 Force 70 HP lower unit oil change

Is this the correct one?

http://www.sears.com/shc/s/p_10153_12605_00920896000P?prdNo=3&blockNo=3&blockType=G3

 

[Cannondale]

Re: 1991 Force 70 HP lower unit oil change

This is what I've always used on stubborn screws like lower unit drain/fill screws:

http://www.sears.com/shc/s/p_10153_12605_00941588000P?prdNo=4

3/8" x 12" flat blade screwdriver, square shank. Very stubborn screws may need an adjustable wrench on the shank for increased torque, but that driver has yet to fail me. It also doubles as quite an effective light duty pry bar....

 

[Frank Acampora]

Re: 1991 Force 70 HP lower unit oil change

There's two links that will work. I like that driver: Mine is Sears and older, BUT it does not have the hand guard. That red one is better than mine.

 

[wifisher]

Re: 1991 Force 70 HP lower unit oil change

Make sure to do the top one first. Just in case.

 

[Chris73Cobia]

Re: 1991 Force 70 HP lower unit oil change

I think I'm going to the marine store to get 2 new plugs before I do this, so in case they are totally shot when I'm done, probably a worthwhile investment.