1979 Evinrude 100 HP Lower unit removal

I need to remove the lower unit to get it straighten as it got bent in sand. I have removed the two bolts on each side and the one behind the trim adjustment but it will not come off. What else do I need to do? If possible please refer to a diagram with your instructions. Thank you.

Re: 1979 Evinrude 100 HP Lower unit removal

You need to remove the shift rod pin shown as #66 in the schematic.....



It will be located below the lower carb on your motor.

Re: 1979 Evinrude 100 HP Lower unit removal

You should have another bolt forward of the trim tab bolt. This one is longer and possibly more difficult to remove. I used an electric impact wrench to remove mine. And of course, don't forget to let the shift rod go.

Re: 1979 Evinrude 100 HP Lower unit removal

Did you remove the trim tab and the hidden bolt above it?

Re: 1979 Evinrude 100 HP Lower unit removal

If the lower unit has dropped at all after you removed the bolts there are no others, there are two each side and one under the trim tab so 5 in total plus the trim tab bolt.....if it still wont come off it will be the pin in the shift rod keeping it there.

Re: 1979 Evinrude 100 HP Lower unit removal

Thank you for your replies. I won't be able to get to my boat until after the new year. I have removed 5 bolts, four the same length and one longer. The unit has not dropped any and is still mounted solid. I have not removed the trim tab or any hidden bolt above it. Is there another bolt there? Clarification please or I can wait and find out when when I remove the trim tab. If there is one there it would make 6 bolts plus the trim tab bolt. I also have not removed the shift rod pin or bolt. So I have more work to do. The boat is in an enclosed shelter with the motor in the lowered position and touching the back wall and the end of the tongue touching the door at the other end. The boat is on a trailer and there is about 12 inches clearance between the bottom of the lower unit and the ground floor. If I'm successful in getting it loose, does my motor have to be in the raised position to give the necessary clearance to pull it off. If it does I'll have to take a snow blower and a four wheel drive out there to get it out of the shelter enough to raise the motor. I would like to get the repairs done before the summer rush so I don't want to wait until spring.
Thanks
Ray

Re: 1979 Evinrude 100 HP Lower unit removal

Yes, there is another bolt under the trim tab......it needs to be removed to access it.

Just checked the schematic again. You are correct, there is another fastener i did not see at first glance.....so its 6 in total plus the trim tab bolt. Sorry bout that.

Re: 1979 Evinrude 100 HP Lower unit removal

mark1961 said:

Yes, there is another bolt under the trim tab......it needs to be removed to access it.

Just checked the schematic again. You are correct, there is another fastener i did not see at first glance.....so its 6 in total plus the trim tab bolt. Sorry bout that.

Click to expand...

Thanks that answers that question. The other question is are there rods attached to the lower unit when it is removed such as the shift rod and drive shaft? From this info I can estimate how much clearance I need.

Re: 1979 Evinrude 100 HP Lower unit removal

Yep, driveshaft and shift rod stay in the LU, they are both roughly 21 inches......are you concerned about ground clearance? Have the motor tilted all the way up when dropping/installing the gearcase and you will have no issue.

Re: 1979 Evinrude 100 HP Lower unit removal

Agree + 1 with above..............

Re: 1979 Evinrude 100 HP Lower unit removal

mark1961 said:

Yep, driveshaft and shift rod stay in the LU, they are both roughly 21 inches......are you concerned about ground clearance? Have the motor tilted all the way up when dropping/installing the gearcase and you will have no issue.

Click to expand...

Yes I'm concerned about ground clearance. I need to know if I had to raise the motor or not. Thanks you answered my question. The answer tells me I would need to take out a four wheel drive and snow blower to my cabin which is about 90 miles away and I need to clear a 1/2 mile driveway which has about 18 inches of snow. The boat is on a trailer with the back of the motor touching the back wall of a garage and the end of the tongue touching the entrance door. I need to decide if I should wait for spring thaw or not.

Re: 1979 Evinrude 100 HP Lower unit removal

Wait for spring. It doesn't take that long to do the job you want to do. I'm from Northern WI and I know what snow is. Burrrrr!