Draining Lower Unit Lube

Jango

Petty Officer 2nd Class
Joined
May 15, 2002
Messages
132
Would like to drain and refill gear lube in lower unit, but do not know how lube will drain since both VENT and FILL holes are next to each other above cavitation plate,well above gears. Does one tilt motor out, which should drain most lube? How to refill?<br />Motor is an 85HP Force and has a Screw near bottom of unit, but does not look like a drain port. Still waiting for a recently purchased Motor Manual which may answer these questions?<br />Thanks for any help<br />John
 

tuxcedo88

Seaman Apprentice
Joined
Mar 24, 2002
Messages
40
Re: Draining Lower Unit Lube

screw at the bottom of the unit is the screw that needs to be removed along with the fill screw. after the unit is empty you fill the unit from the bottom, forcing fluid into the unit until it comes out the fill hole. you then replace the screws ( with new washers if needed back into the holes you removed them from ). Happy boating
 
D

DJ

Guest
Re: Draining Lower Unit Lube

Jango,<br /><br />Tuxcedo88 is right about the screws. PLAN on putting new washers on them-they're cheap. Most Merc. dealers would have them. Make sure to have the model number of your engine with you. It's located on the bracket that bolts the engine to the transom.
 

Scottj25

Seaman
Joined
Jun 20, 2001
Messages
51
Re: Draining Lower Unit Lube

I had this motor and also the manual that went with it. here is how the manual said to replace the lube.<br /><br />1. Remove bottom drain screw.<br /><br />2. Remove vent screw.<br /><br />3. Remove fill screw.<br /><br />4. After draining replace drain screw.<br /><br />5. Fill lower unit using the fill hole.<br /><br />6. Fill unit lube starts to come out of vent hole.<br /><br />7. Cap both holes, make sure your using a new washer on the screws for all three hole.<br /><br />at this point I would let the unit set in the full down for a day or two and open up the vent and fill to top off, just in case I had any air traped in in the lower unit.<br /><br />The motor was a 1984 and was running strong when I sold it this year to buy a larger boat.
 

Rex

Chief Petty Officer
Joined
Aug 12, 2001
Messages
424
Re: Draining Lower Unit Lube

LET FILL THE CAR TO THE TOP JUST AS LONG<br />IT does not have air in it.<br />I was just wondering how long that car would last.<br />Rex a.
 

Down South

Petty Officer 1st Class
Joined
Aug 7, 2001
Messages
333
Re: Draining Lower Unit Lube

I've never heard of filling any lower unit from the top. The standard procedure has pretty much always been the same. Remove both (drain, located at the bottom of the foot) and (Vent, oil level, located around the cavation plate) screws. Drain all the oil out leaving the motor in a vertical position. Fill the lower unit with oil by forcing it in the drain hole till it comes out the vent hole. Replace both screws with new washer or seal. Later, remove the vent screw and add oil with a squirt type oil can to top off if needed.
 

wvit100

Chief Petty Officer
Joined
May 6, 2002
Messages
416
Re: Draining Lower Unit Lube

The is a slotted screw on the side of the lower unit near the bottom. DO NOT REMOVE THIS SCREW. It holds part of the shifting lever and if you take it out you will have to take the whole thing apart to get it back together.<br /><br />There is a small allen screw on the very bottom of the lower unit that you will need to remove that will let the oil drain. This screw is hard to remove sometimes, make sure you have a good set of allen wrenchs and be careful with it.
 

Scottj25

Seaman
Joined
Jun 20, 2001
Messages
51
Re: Draining Lower Unit Lube

I'm not trying to start a debate but on this model and make of motor each hole is labeled<br /><br />1. Vent<br />2. Fill<br />3. Drain<br /><br />The vent and fill are side by side and on top of the lower unit.<br /><br />Why I don't know but they are and the Manf. felt it was a better ideal, right or wrong this is the way it is.
 

Mumblerone

Petty Officer 1st Class
Joined
May 12, 2002
Messages
344
Re: Draining Lower Unit Lube

If you don't fill from the drain hole you do at your own peril. When you fill from the bottom up you get all air but most importantly you fill the cavity with oil 'completely.' When you fill from top your never sure it's all full (the oil just runs through). Are you sure the lable say "fill" or full. Seriously you'll burn the gearcase out if not done properly.
 

Scottj25

Seaman
Joined
Jun 20, 2001
Messages
51
Re: Draining Lower Unit Lube

Having had this motor for a lot of years the labels are correct.<br /><br />I now have a mercuriser and yee the lube is put in at the bottom, but as I stated on this o/b the manuf. wanted the lube put in the top.<br /><br />Also the manual also stated that the lube be put in from the top. why force wanted it done this way who knows......maybe that's why Force is no longer making motors.<br /><br />But I will say this I never had a problem with this o/b outside of replacing the starter and stator. Maybe I'm one of few who reads the manual and got away with it.
 

Jango

Petty Officer 2nd Class
Joined
May 15, 2002
Messages
132
Re: Draining Lower Unit Lube

My Motor has a total of 3 "Lube" holes in the lower unit. Two marked "FILL" and "VENT" on the top and a small 1/4 or 5/16 set screw type on the very bottom for "DRAINING". In addition a slotted head screw recessed on side of the gear housing. This one is undoubtedly for gear adjustment (a no-no to fiddle with, I quess)<br />I never saw the drain hole before it was mentioned, Thanks for filling me in on this. <br />I drained and refilled per Scott25,s advice. Will check the level in the next few days, before,I put it in the water.<br />By the way, I put more in than I took out - The old oil looked OK (not brown or milky)<br />Thanks a bunch to everyone<br />John
 

Down South

Petty Officer 1st Class
Joined
Aug 7, 2001
Messages
333
Re: Draining Lower Unit Lube

My apologies Jango, :( I'm not very familiar with the Force. It's a first for me on filling the lower unit from the top. I understand why the fill and vent plug now. <br /><br />Down South
 

Jango

Petty Officer 2nd Class
Joined
May 15, 2002
Messages
132
Re: Draining Lower Unit Lube

Sailboaty, I live in Parkersburg and do most boating on the Ohio.<br /><br />Appology not necessary DownSouth. I too have always drained and filled from the bottom. I also have 2 Mercurys, a 4HP and a 20HP. Bought this boat recently and really never looked at a FORCE before. What's most important is, ALL you guys who took the time to try and help. The bottom line is I probably found the solution to the problem. Thanks for responding DownSouth<br /><br />John
 
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