I have a 2006 Merc 115 4-stroke that I am trying to remove the gear housing so I can replace the water pump. according to the manuals and videos and i’ve looked at there are 5 nuts that need removal. I’ve removed all 5 and their washers. Threaded one back on a couple of turns to help catch the housing when (if) it come loose. Motor is tilted up and in forward gear. The gear housing is stuck. Can’t get any separation to try and pry it apart.
Any suggestions for how to break this free. Not sure if its stuck at one of the posts or drive shaft is frozen.
Did you take off the trim tab and remove the bolt hiding under it? Also, many motors require that you unbolt the shift shaft at the power head. I’m not sure on that particular engine. Some are spline joints now and don’t require disconnecting.
Other than that, corrosion is probably holding it together. Try frapping downward on it with a big rubber mallet and try to create a crack, then drive wooden wedges in the crack to separate the housing. The aluminum casing is soft and easily damaged, so use wood and rubber to beat on it, not a steel mallet! Spray a good penetrating oil anywhere you can and let it sit 12 hours, then beat on it some more:smiley:
Edit: In our salt water it’s a good idea to remove the gear case and prop once a year and grease everything good, whether it needs it or not. This way when you need to get it apart you can. If you wait 3 or 4 years to try to take the prop or lower unit off, it’s not usually coming off without a lot of work, damage and expense.
Capt. Larry Teuton
Cracker Built Custom Boats
Marine Surveying & Repair
I removed 2 on each side and 1 directly under the sacrificial anode. i do not see where another (6th) bolt would come into play. I do have the spline joint on the shift shaft. I did spray down all 5 posts yesterday. Hopefully that will help towards tonight’s round.
thanks for the advice on removing the casing every year. That will be added to the list along with trailer wheels.
Yeah it’s probably just corrosion holding it together, either at the studs or the drive shaft at the power head. I have fought many of them and usually win, sometimes not[:I] Put a 2X4 block on the anti-ventilation plate and hit it about 6 times, then same for the other side, back and forth until you wear down. You can heat the area around the studs, but then you screw up the paint, so that’s a last resort.
Next to last resort, try to rig up a small screw or bottle jack between the engine mount and the AV plate, using blocks of wood between all aluminum parts. You can almost always jack it apart if you can rig a solid bite for the jack.
Capt. Larry Teuton
Cracker Built Custom Boats
Marine Surveying & Repair
Don’t forget the one in front of the Lower unit.
I was thinking Merc’s had 6 bolts/nuts. One in the very front of the lower unit, one under the trim tab, and two on each side.
Front of the motor is a “stud” with a lock-nut.
That thing will accumulate a lot of corrosion where the stud passes through the housing. Soak things with PB Blaster. Forget about WD40.
I had to use a hydraulic porta-power last year to get mine seperated, Be gentle but forceful.
