Size of Jam, nut, lower mount nut and top adjustment align nut sizes for a 3.0 Merc.?

[JWebber]

Doe's anybody know what size these nuts are? The jam nut looks the same size as the lower mount nut,and the adjustment also looks the same size, But do not know the size! Also how is the heck to you loosen these on a 175 bayliner BR with 3.0 Merc. engine?? It's real tight in there with a small area to work with. Is there a special off set wrench that the dealers use??

 

[Don S]

Re: Size of Jam, nut, lower mount nut and top adjustment align nut sizes for a 3.0 Me

I don't recall right off what size it is, 1-5/16" sticks in my mind.
All you need is some vernier calipers and measure it.
What I did was cut the end of an open end wrench off just long enough to get past the mount. Then welded a socket on the end of the wrench. Then you can use an extension and ratchet to turn it for adjustment.
I picked up the right size wrenches years ago, and used the cheapy wrenches with cutoff and/or bent handles to adjust by hand when the pressure is off the lock nut.
I have also had to remove the mount completely while the front of the engine was held with a hoist to break the locknuts break free.

Just one of those "do what you have to do" type things for when the designers make things inaccessable.

 

[JWebber]

Re: Size of Jam, nut, lower mount nut and top adjustment align nut sizes for a 3.0 Me

Don S, Good info, and on the same thought pattern here. 1-5/16" size is correct I confirmed with Mercury this morning etc.. So I guees I'll need two cheapo 1-5/16" wrenches, and some engineering tool make up. Similar to a crow foot setup wrench? I see the tool make up But how in the hell did you get the right leverage to even crack them loose, I'm in a strange postion to even try to loosen them. Really trying to understand that part! LOL!

 

[Don S]

Re: Size of Jam, nut, lower mount nut and top adjustment align nut sizes for a 3.0 Me

The tool will be similar to a crows foot, but the square hole for the ratchet is too close to the wrench opening on a regular crows foot, and will push the wrench off the nut.

 

[brntrt]

Re: Size of Jam, nut, lower mount nut and top adjustment align nut sizes for a 3.0 Me

Don S, Good info, and on the same thought pattern here. 1-5/16" size is correct I confirmed with Mercury this morning etc.. So I guees I'll need two cheapo 1-5/16" wrenches, and some engineering tool make up. Similar to a crow foot setup wrench? I see the tool make up But how in the hell did you get the right leverage to even crack them loose, I'm in a strange postion to even try to loosen them. Really trying to understand that part! LOL!

Don't you just love boat builders???? They have no concept of what it takes to do repairs after the boat in built. Back in the day when I did this for a living, I would call them "martini engineers" they would go to lunch, have a few drinks, and then design a boat. Be thankful........I had one boat, ( v-8 ) that I had to pull the engine to change the spark plugs Lots of them v-8s that we had to pull the motor for starter repairs

 

[JWebber]

Re: Size of Jam, nut, lower mount nut and top adjustment align nut sizes for a 3.0 Me

Thats just crazy! I've seen my share over the years and seeing other peoples boats per manufacturer etc.. If they made the front engine cover panel ( no my boat) have a removeable access panel if would be too dam easy! But! not the case here! LOL! In the above photo you can see were they tried to apply some room, like a notched out area right in front, but of course not enough room for nothing.

So I'm going to do a custom tool build like DonS suggested.
Habor freight has these!