280 hinge pin removal

I am in the process of "trying" to remove the keeper bolts and hinge pins in my 1979 280 OD. I have gotten lucky so far and managed to get one side keeper bolt out by using some heat. No such luck on the port side. At this moment I have the upper and lower units removed so I am only dealing with the intermediate and swing arm. I even have the engine and flywheel cover removed.

At this moment I have several concerns about how much heat to use.
I have built a diverter dam system around the top of the OD where it bolts to the transom and ran a small trickle of water so it runs down to keep the boat gel coat and hull from getting hot.
My concern is how much heat can I apply without damaging the seal between the transom and OD plus damaging the plastic sleeves (bushings)that the swing arm rides on.
If I damage any of those and am not able to get the pins out I am up the creek without a paddle and would be in a worse condition than I am right now.
I have read as much as possible on this site in regards to this and realize that I do not want to break a bolt or I might as well "pack it in"

Of course the 4 bolts that hold the exhaust "Y" on are also "salt" frozen so there is another challenge if I wanted or needed to take the entire assembly off the boat.

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Glasply21 said:

I am in the process of "trying" to remove the keeper bolts and hinge pins in my 1979 280 OD. I have gotten lucky so far and managed to get one side keeper bolt out by using some heat. No such luck on the port side. At this moment I have the upper and lower units removed so I am only dealing with the intermediate and swing arm. I even have the engine and flywheel cover removed.

At this moment I have several concerns about how much heat to use.
Use a small Mapp Gas torch. You won't be able to apply enough heat to damage anything.
The rope gasket is replaceable, should it come to that.
You'll want new hinge pin bushings anyway.

Once warm, drive the hinge pins outwards with a brass or aluminum ONLY drift punch.



If I damage any of those and am not able to get the pins out I am up the creek without a paddle and would be in a worse condition than I am right now.
I have read as much as possible on this site in regards to this and realize that I do not want to break a bolt or I might as well "pack it in"
With heat applied, work the keeper bolt in both directions until it frees up.
Worst case, you'll need to drill it out.
If you loose the female threads, there is a fix (more on that later if need be).



Of course the 4 bolts that hold the exhaust "Y" on are also "salt" frozen so there is another challenge if I wanted or needed to take the entire assembly off the boat.
You will apply the heat to the Y-pipe where the thread inserts are housed.

Click to expand...

Hello Rick, thanks again for sharing your wisdom. I will try once more first chance I get. Should I be concerned at all on how hot the gelcoat and transom get? As for the keeper bolt the head has gotten a bit larger than normal so I have ground down a wrench to keep the tightest fit possible so I don't round the center out.
The transom "gasket" from what I see on the outside is black and appears to be some type of rubber material.

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Glasply21 said:

Hello Rick, thanks again for sharing your wisdom.
Not sure if it's wisdom or just experience.... but you're certainly welcome.

Should I be concerned at all on how hot the gelcoat and transom get?
I've come up against a few stubborn ones, but have never needed so much heat as to worry about the gel coat.
Your idea with the water is good, if concerned.

As for the keeper bolt the head has gotten a bit larger than normal so I have ground down a wrench to keep the tightest fit possible so I don't round the center out.
Good idea. These are SS, and would be bear to drill out!

The transom "gasket" from what I see on the outside is black and appears to be some type of rubber material.
Yes, a rope style gasket.
These typically survive for a second time around.
We can use a small amount of 3M 4200 or Boat Life "Life Caulk" in the grove and at the surface if need be.

You will want to replace the 6 carriage bolt "shank" seals, and again use 3M 4200 or Boat Life "Life Caulk".

Click to expand...

Your transom shield mounting bolt holes will be (should be) lightly counter-sunk for seal compression. (I've seen some that were not!)
Easy to do if not!

Updated drawing:

Progress or lack there of on hinge pin removal today resulted in the bolt finally breaking after apply a tremendous amount of heat for a very long time. It broke about half the depth of the pin diameter so I will give an honest effort in an attempt to drill it out. At this point I am sure the exhaust Y bolts will break also.
At this point I am willing to break those bolts and buy a Y pipe that I have found in great shape and what I feel is a fair price.

For anybody who can help me with this next question. When it comes to the transom shield will any newer model 280 fit? I have also found one in great shape but the keeper bolts are positioned to enter from a horizontal angle unlike mine which enter vertical from the top. Is that the only difference between them?
Thanks

As for your replacement transom shield question:

During your year model, the AQ200 and AQ225 were found in the B versions. The B version exhaust Y-pipe was 3" inlet and single exhaust relief.
Your now engine may be different from what was OEM.

If 3" inlets, the 4 cylinder single exhaust relief transom shield can be used.
If 95mm inlets, this will be double exhaust relief, and must be replaced with the same.


BTW, there is a decent fix for when the hinge pin keeper bolts and/or threads are gone.
If interested, shoot me a PM with your name and email address.


.

When I had this happen to me on my old AQ100 drive, I drilled and tapped (using helicoil insert) a new hole in the mounting boss of the hinge pins at right angles to the original hole ( it stuck out aft). I installed a lock nut on the bolt so that the bolt could be adjusted and locked to "retain" the hinge pin and did not "jam" it.

Thanks for the advice, I will attempt to drill out the broken assembly and try to make a correction.

Glasply21, the hinge pin keeper bolt thread insert is deep within the bore.
In my opinion, to successfully extract the broken the bolt fragment, you'll need the service of EDM (electric discharge machining).
This would involve the removal of the shield, and would be somewhat expensive.

Here's a simple and effective cure/fix that will likely last the remaining life of this boat.
This will not only hold the hinge pin in the bore, but will also prevent unwanted rotation.

Rick, once again thanks. I will see what I can do to drill the bolt to clear the hinge pin and check out the EDM method. Time to try and get some work done now.