Page 56 - Lady Bass Digital Magazine Classic 2022
P. 56
Tips for Regular Maintenance
Part 7: Lower Unit
Next, it is time to focus on the lower unit. Most manufac- tic pump tube fitting into the
turers recommend you change out the lower unit oil every bottom drain plug. Be careful, it
100 hours of operation. Make sure you check your own- is plastic. Once secured, begin to
er’s manual and use the correct lubricant for your specific pump the oil into the lower unit.
engine. It takes about 15-17 ounces to
fill. When oil starts coming out
The tools you will need are the gear lube, a good screw- of the overflow (top hole), the
driver, a set of gloves to keep your lower unit is filled. Replace the
hands from getting oil all over them, top drain with gasket or over-
and a good large tub to capture the flow plug first and tighten. This
oil. There is a kit with a screw attach- will create a vacuum and reducing the leaking from the
ment for filling if you choose to use lower drain plug. Remove the plastic pump tube fitting and
this. Select a container with a screw replace the lower drain plug with gasket and tighten. Clean
cap or lid will allow you to recycle up any oil.
the oil. The final things you will need
are a lot of rags to wipe off and clean When you drain the oil, one of the things you want to look
the motor after you are done. for is if there is a milky or mustard color. The oil will be
naturally thicker, but if the milky or mustard color is pres-
If you are working on older ent, this is an indication that water has gotten into your
Mercury engine, you must lower unit. If there is no milky or mustard color, there
remove the prop to access the can still be issues. Be sure to check the oil for any metal
lower drain plug for changing shavings. A few shavings are normal, but the presence of
the lower unit oil. On other a lot of metal shavings signals unnecessary wear and tear.
outboard engines, the process is If either of these are present, you need to get your motor
the same for draining the lower to your dealer to let them look at it and change any seals
unit. It is a matter of locating necessary, or to find out if there is something more serious
the upper and lower drain plugs. going on.
On the new four strokes, both drain plugs can only be ac-
cessed by removing the prop.
On the four stroke engines,
you still start by removing
the lower drain plug first. Be
sure to get the yellow rubber
gasket that comes off with it.
Check for damage and re-
place if necessary. Nothing is It is critically important to wipe the spindle and the hub
coming out yet because it is making sure there is no debris. The hub has splines that
totally sealed. Fluid will start should like up with the gaps on the spindle. Once the hub
to drain once you break open the upper drain plug. Under is one, you can now put the prop back on. Be sure to put
normal conditions it will take about 30 minutes to drain all the parts on in exactly the reverse order in which they
due to the thickness of the oil. were removed. The big washer goes on first, followed by
the flat washer. Next will be the bowed washer. You want
Once the oil has drained, trim up a little to make accessing the bow out toward you when you install it. Finally put the
the drain plugs a little easier. Also, this is a great time to prop nut on and tighten it down. Remember to use a brace
do a little cleanup of the excess oil. Next, thread the plas- to secure the prop when tightening or loosening for that
matter.
54 Lady Bass Anglers Association Maintenance Tips- Part 7: Lower Unit