Deep Sockets Will Not Fit - Gearcase Removal

[97mirage]

Trying to remove gearcase from midsection (1981 225 Merc 20" Standard Midsection) and cannot get any of my sockets to fit into the hole to access the nut that connects the bottom of the midsection to the gearcase. I am referring to the small round cavity in the back that is usually covered with the little round dust cap. I have an enormous selection of sockets but the outside diameters are all too large to go through the inside diameter of the little cavity.

I special ordered a 5/8" deep socket (1/4" drive) thinking this would be the one to fit into the little hole and even it's too big. What tool is used? It appears to be a 5/8" nut that I am trying to grab and the head on the bolt (the one on the outside that I CAN access
is 9/16"). I do not recall ever having this problem in the past. Any thoughts? Thanks.

[vnemous]

I think mine was a thin walled 10 or 12 mm if I remember but its been a while. I recall I only had on socket that would fit. I believe that screw holds the zinc on but the zinc has to come off to get to the screw that does hold the lower on. JMO

[RRRevinrude]

you need a snap on socket--much thinner walled-it will fit

[transomstand]

It appears to be a 5/8" nut that I am trying to grab and the head on the bolt (the one on the outside that I CAN access
is 9/16"). I do not recall ever having this problem in the past. Any thoughts? Thanks.

This is confusing. There is a 3/8" bolt holding the zinc. It should be a special bolt with 7/16" head on it. I'm not sure where the 5/8" nut comes in:confused:

[johnboy 88 vegas]

you need a snap on socket--much thinner walled-it will fit


I can second that. The 3/8 drive standard deepwell definitely fits but I know i've done it a long time ago with cheap sockets but done remember what brand.

[astro@ptd.net]

I had the very same problem. I finally found a deep socket 1/4" drive from a cheap multi set from Lowes, their Kobalt line of tools. that's the only one I could find that fit. None of my other more expensive sockets would fit. The mechanic at my local marina said he even took a grinder to one of his sockets to get one that would fit and he has it market as such just for that job. Go figure!!

[Ron V]

The mechanic at my local marina said he even took a grinder to one of his sockets to get one that would fit and he has it market as such just for that job. Go figure!!

Yep...what he said. You can go broke buying special tools or you can make your own. I use a 6-point 3/8" drive Craftsman deep well, but it has been ground just a hair in the middle.

[BUSHWACKER]

On the first day GOD created man and Snap On tools to giterdun right! :thumbsup:
On the second day HE created all other tools to heat, beat and bend and grind on if a SnapOn wouldn't do it! Oh yeah and women too! :D
Many years ago I did a job with a SnapOn wrench that another younger guy could not do with is craftsman on a Ford, he traded his whole box and all tools in the next day the SnapOn man came in. $$$$$$$$$$$$ :eek:

[tlwjkw]

This is confusing. There is a 3/8" bolt holding the zinc. It should be a special bolt with 7/16" head on it. I'm not sure where the 5/8" nut comes in:confused:

What he said! There is no 5/8 in that hole. Should be 3/8 bolt with a 7/16 head........Go back with stainless allen head screw from Ace Hardware. Makes life lots easier next time...........

[Liberator*21]

What he said! There is no 5/8 in that hole. Should be 3/8 bolt with a 7/16 head........Go back with stainless allen head screw from Ace Hardware. Makes life lots easier next time...........

I totally agree, I've replaced every bolt possible on my motor with stainless Allen Heads where ever possible, makes life so much easier when there's work to be done.

[astro@ptd.net]

What he said! There is no 5/8 in that hole. Should be 3/8 bolt with a 7/16 head........Go back with stainless allen head screw from Ace Hardware. Makes life lots easier next time...........

Now that's a great idea!!!!!!!! Why didn't I think of that!! A trip to the hardware store is in order. I've seen those style allen head bolts at the hardware store while searching for fasteners for other jobs but not in SS. they were a black metal. Would those work or will they rust?? I don't know what metal it is.

[97mirage]

Thanks for all the responses...

I actually have gone the Snap On route...that was the special order socket that I mentioned in my original post that did not fit. I also tried grinding one of my craftsman sockets but stopped thinking I was not going to be successful. I guess I could keep on going or I will try to find some thin walled sockets and, once removed, will use different fastener. Thanks again, guys.

[Ron V]

One thing all of us failed to mention was that the real problem is Mercury building the damn thing that way to begin with. I guess they figured it's small potatoes compared to the task of actually getting the gearcase back ON after you're done working on it.

[vnemous]

I believe you can get allen head screws for both of them so you dont have this problem.

[Tom Foley]

I think you ordered the wrong socket bro !!:D No 5/8" headed bolt in that hole !!!

[ChrisCarsonMarine]

????? Just not that difficult guys... OLD mercs used an Allan screw,I think up to around 1970,then around ten years of 7/16 twelve point,then on through to recent times a 1/2 six point.Mercruisers used the steel Allan head longer than the outboards,they are interchangeable in thread size but not always in access size.The thread size is 7/16x14,and would have an auto parts bolt head size of 11/16,shine a flashlight down the hole and look,,,,if there's a BIG head down there it just means the last guy bolted on the trim tab zinc before installing the gearcase,about 1/2 the ones we service are missing the bolt under the zinc.Anyway,there's no call for an extraordinary socket in normal circumstances,Chris

[silverbullet02]

I've never had a 1/2" 3/8 drive not fit?

[Tom Foley]

????? Just not that difficult guys... OLD mercs used an Allan screw,I think up to around 1970,then around ten years of 7/16 twelve point,then on through to recent times a 1/2 six point.Mercruisers used the steel Allan head longer than the outboards,they are interchangeable in thread size but not always in access size.The thread size is 7/16x14,and would have an auto parts bolt head size of 11/16,shine a flashlight down the hole and look,,,,if there's a BIG head down there it just means the last guy bolted on the trim tab zinc before installing the gearcase,about 1/2 the ones we service are missing the bolt under the zinc.Anyway,there's no call for an extraordinary socket in normal circumstances,Chris

Yep ...just drill the hole to the newer size plug and voila ....done .

[Ron V]

I stand corrected on having to grind my socket. I just went out to the garage and checked. A 6 point Craftsman 1/2" deep well 3/8 drive just barely goes in. I was thinking of a 13mm deep well that I had ground at one time and is laying in my toolbox. That one also fits but is of course a little loose on the bolt because the bolt is 12.7mm. Not sure exactly why I ground that socket. Must have been for something else. That said, I could see where maybe not every brand or type of socket would fit through.

Chris - I can't quite understand what you're trying to say. Why would the size of the bolt head have anything to do with the order that the last guy assembled it in?

[ChrisCarsonMarine]

Ron,the bolt were discussing does not help hold the gearcase on,it holds the zinc trim tab,only.However,there is a bolt going UP through the gearcase into the rear if the mid...and the trim tab covers the access to it,it seems lots of folks don't bother to install it.I would recommend using it,but of you didn't you would not need to remove the trim tab to remove the gearcase,so you could bolt the tab on with a larger headed bolt,and then install the gearcase,the next guy in line won't get a big enough socket down the small access hole in the mid...,Chris

[Ron V]

I knew which bolt you were referring to, just came across strange the way you worded it I guess. It "could" be a larger headed bolt if it was put together in the wrong order, but wouldn't "necessarily" be. Then again if someone doesn't bother to install the bolt under the zinc, I guess substituting the other bolt with a bigger one for no reason wouldn't be all that far fetched.

People who don't install the bolt under the zinc are either really bad at counting how many bolts they have left, or are not smart. Mercury wouldn't spend the $0.79 on the bolt if it didn't serve a purpose.

The allen bolt must be on the really old Mercs. I'm pretty sure my dad's '71 Merc 650 has a regular hex bolt but it's been awhile so I can't remember for sure.

[johnboy 88 vegas]

Lot of people dont install the bolt under the cav plate cause there really is no need for it on a race boat. Really what pupose does it serve when theres two studs right in front of it? One of my buddys didnt do it on his 200 merc and used the cavitation plate for his swim ladder and it cracked the cav plate where the zinc piece is up top. If ya dont put the bolt in atleast put a warning sticker on it for fatasses steppin on your cav plate to get out the water. After seein that I put my bolt back in where it belongs.

[ChrisCarsonMarine]

I run all the bolts and nuts,I want the odds in my favor,I've seen many gearcases vibrate loose and ruin the mateing surfaces on the mid and lower and even break the driveshafts.Ive fad 2completely come off,back in the 2 blade days,Chris

[transomstand]

I've seen many gearcases vibrate loose and ruin the mateing surfaces

:iagree:

Same here, I always run all the bolts, and recheck them on a regular basis. It's not just the rear bolt holding it, the rear bolt also locks the case to the rear dowel pin.

[johnboy 88 vegas]

Yep your right but people who go through gearcases like a city worker eatin candy bars tend to leave that last bolt out. Which yes it does take another 35 seconds to pull the zinc (without a air gun) and another 30 to get the bolt out (on a freshwater motor).(Saltwater add 1 hour)lol. So if this was a circuit race with a Nascar pitcrew you'd be screwed on bolt #1 since most have loctite on em from the factory. Eihter way you look at it the bolts were there for a reason from the factory so some people learn the hard way...like my buddy.

[donmac]

the rear bolt has more leverage to keep the case in place than all the others,if you think about the prop location and side forces,you won't run without it!

[ChrisCarsonMarine]

Correct

[johnboy 88 vegas]

10-4 we should start a thread with what stuff people leave off on a regular basis for good reason or not....just for shts and giggles