Tools Needed:

  • Sockets :- 5/8″ socket
  • Wrenches:-  5/8″ wrench
  • Sealers/ Lubricants:- Grease
  • Miscellaneous: – Ratchet,  6″ socket extension,  Large flat blade screwdriver,  Alignment tool (optional),  5/16″ Allen wrench,  3/8″ Allen wrenchStern Drive Assembly

NOTE: If you bought a “Complete Unit” with the “Complete Install Kit,” you can skip ahead to Step 2. If you did not and are reusing your old hardware, you will need to separate your old drive.

1.1 Remove the trim tab bolt with a 3/8″ Allen key. Some of the older drives may use a 5/16″.

1.2 Remove the bolt that is under the trim tab. Use the 5/16″ Allen key.

1.3 Remove the front locknut. Use a 5/8″ wrench or socket.

1.4 Remove the two back locknuts. Use a 5/8″ socket.

1.5 Remove the two side locknuts. Use a 5/8″ wrench. It will be necessary to separate the halves slightly before the side nuts can be removed all the way. To aid in separating the halves, you may want to leave enough room to get a screwdriver between the side nuts and the upper housing, to give you a place to pry.


2.1 Make sure that the water pipe pieces are in the proper areas. The water tube should be pushed into the grommet on the upper housing.

2.2 The other grommet and plastic guide tube should be in the water pump housing on the lower. Also make sure that the quad ring is in its proper spot and the bolt for the trim tab is in its hole. Put some marine grease on the vertical shaft splines.

2.3 Install the brass shift shaft into the upper housing.Insert the brass piece, then install the washer, and then the cotter pin.

2.4 The two halves are now ready to be put together. You may find it easier to use two people to do this. As you bring the halves together, the first thing that needs to line up is the copper water tube with the plastic tube guide.

2.5 The next thing to line up is the vertical shaft. At this point put a large screwdriver in between the two halves so they do not go together all the way. It may be necessary to rotate the u-joint assembly clockwise to get the splines aligned. Now, the only thing holding it from going together completely should be the screwdriver that is in between the halves.

2.6 With the screwdriver separating the drive a little bit, you can get the alignment on the brass shift shaft correct. Rotate the brass shift shaft clockwise. You will need to rotate the propshaft until you feel the clutch lock in. If the propshaft is ratcheting you are turning the wrong direction. The brass piece should be pointing straight ahead. If it is not you will need to pull the brass piece straight up to disengage the splines and rotate it to the straight forward position. Then push it straight down onto the splines.

2.7 Now you can start to install the hardware. First install the two side nuts. The drive has to be separated do install them, so you should still have the screwdriver in between the halves. Once both of the nuts are started, you can then pull the screwdriver out and tighten the nuts.

2.8 Then install the two nuts in the back of the unit and the 5/16″ head Allen bolt.

2.9 Install the front nut and the trim tab. Spin the prop after the trim tab is installed to check for clearance.