Below  you will find information on removal and replacement of Mercruiser outdrives, series # 1 and Alpha Gen I's.  We do not claim to be experts in all fields.  Nor can we promise to be correct on all issues.  Nor can we address the content of these pages.  (Please read our legal disclaimer page)

But, I hope you will find this page useful.  We want to thank Aftermarket Marine for their technical assistance with this page.  Aftermarket Marine is a supplier of high quality aftermarket parts for outboards, inboards, and inboard / outboards to BoatFix.

1)           Start with outdrive down and control box in forward gear.

2)           Remove the nuts holding the rearward trim & tilt cylinder anchor pin, save parts.

3)           Pull the trim & tilt cylinder heads off of the rear pin, save parts.

4)           Remove the six 5/8 locking nuts & washers from the outdrive at the bell housing, save parts.

5)           Bump the unit downward or lift & drop it lightly to break the seal between the drive and bell housing.

6)           Pull rearward on the unit and it should fall into your arms.  (Be careful, they are heavy.  We suggest two people for this step.)

7)           Clean surfaces of drive and bell housing.

If you encounter problems in pulling off the drive in step 6 above.           

If it wouldn't come off, there are several tricks to remove it.  They are listed below in order of difficulty.

1)           Try a piece of wood or metal across the two ears at the bottom of the ring, lift and drop the unit on it.

2)           Try a piece of wood or metal between the cap front and ring, then lift the unit up to hit it.

3)           Last resort, jam a piece of wood between cap and ring, put the rams back on and trim up.

All of the above steps help push the unit outward and off.  If the problem is that the gimbal bearing has become stuck on the shaft, (a common problem) the bearing might still be there when the unit comes free


1)           After checking gimbal bearing and bellows for leaks, install new outdrive mounting set.

2)           Use a recommended sealant / glue on the large square 'O' ring to the shoulder in the bell.

3)           Use a recommended sealant / glue in the water passage in the groove on the bell.

4)           Replace the "O" rings on the shaft of the drive.

5)           Use a recommended sealant on the outdrive gasket and place it over the studs of the bell.

Unless you have an outdrive mounting dolly, two people will be required for the next steps.

6)           Stand the unit upright and rotate the brass shifter (intermediate shift shaft) clockwise looking down.

7)           The travel of the shifter should be from 10:00 to 12:00 looking down, 12:00 being straight ahead.

8)           Roughly speaking, the shifting should be center of boat forward or 12:00, 11:00 neutral, 10:00 reverse.

9)           The shift box in the boat should still be in forward.

10)           As you rotate the shifter clockwise, turn the prop counter clock wise until it locks.

Never allow the prop to go clockwise or it will rotate the shifter out of position.  If this happens go back to 10.

On the bell housing of the transom plate is the shift arm with a roller on it.  The aluminum slide  piece on the cable tip has two arms, which go to the top with the arms inward.

11) Place the roller from the shift arm between these two arms. The track below the shift shaft should be facing straight ahead.  This is where the top of the brass shifter on the drive slides in upon installation.

12)           With the drive in forward (step 10) guide the tip of the drive yoke through the gimble bearing.

13)           Slide the unit forward.  As soon as it reaches the shift slide, guide the slide into the square hole on the drive.

14)           Look in the right side and recheck the shift arm position and roller position (step 11).

15)           Slide the unit forward until the main shaft hits the coupler spline.  It may not go in at this point.

16)           Keep pressure forward (inward) on the outdrive.  Turn the prop counter clockwise, (it will be hard). This will rotate the shaft.  Continue this until it slides in, keeping pressure inward as you turn.

17)           Once the shaft goes into the coupler the unit will no longer turn counter clockwise.  Do not force it.

18)           Bump the unit forward with the palms of your hands until the drive seats, recheck the roller (step 11).

19)           If the unit resists installation, lift the unit and check that the track on the upper shift is straight and that the brass shifter is going into it smoothly and straight.

20)           Bump the unit the rest of the way on and replace the nuts and washers.

It is good to check the shifting after only two nuts are applied.  If removal is required it saves time.

21)           Replace the trim rams and bushings.

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