Help with frozen Y pipe bolt

HPwannabe

Seaman
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Feb 15, 2020
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63
Hi all,
I have first gen alpha and trying to remove Y pipe. This style has only three bolts, the bottom one being long and having an allen head. Wouldn't you know it was frozen. I eventually ruined the allen socket, so I figured the thing to do would be cut off the head and try to work the pipe off of the bolt shaft. Cut the head off cleanly, but the bolt is frozen inside the aluminum casting. Other two bolts are out and the pipe is "free" - it moves, but it won't come forward due to the frozen bolt.
Any suggestions for how to free it up or otherwise get that bolt out of there? I have oxyacetylene, I could gently heat it while working the pipe. Is there a magic chemical you've found that will dissolve that encrustation that has welded the bolt into the casting?
Thanks.
 

Rick Stephens

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Aug 13, 2013
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Takes a mig welder, but I would, at this point, slip a nut over the shaft and weld it on. The high heat expands the bolt crushing the corrosion, then it cools and shrinks. Put an impact on the nut you welded and run it off.
 

HPwannabe

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Feb 15, 2020
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Thanks for the idea. I'm not sure there's enough room there for a nut. There's essentially no bolt shank sticking out of the hole - it's almost flush. And there's very little room around the boss where the hole is to fit a nut. Could work though. I'm thinking I might try an easy-out.
 

harringtondav

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May 26, 2018
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Sounds like you're into a bare knuckle fight here. I'm assuming your have the exhaust coupler tubes off. I suggest softening the corrosion with Liquid Wrench or another panther pee. A propane/map bottle torch will also work if you can control the fire risk.

A Gen 1 tube may have some some structural weakness, so I'd proceed with a ginger hand. A wood block and heavy hammer, or heavy deal blow hammer delivering smacks close to the flange sideways may break the stuck. The farther up the pipe you strike, the more leverage you gain. But if your pipe is corroded you could crack the pipe.

So I'd hammer low, maybe up to the Y, hand jiggle and repeat. Also your cut off may have left a break thru burr on the bolt which could be resisting. Try under cut grinding the surface of the flange to remove this.
 

Rick Stephens

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You do weld right through the hole in the nut. Flush doesn't change that except you have to start hotter and get a good melt of the stainless bolt. I have removed hundreds that way, learned it in my yute on heavy equipment in the demolition business. Have removed some really big bolt ends and also recently removed a water pocket bolt broken off flush in an Alpha 1.

Problem with easy out, you won't be able to do the weld method after drilling a hole. And, even more so, really hard to stay in the center of a harder bolt than the aluminum housing it is stuck into.

Note, I always apply a coat of VibraTite to every stainless bolt that goes into an aluminum hole. That keeps the electrolysis from freezing it and weakening the bolt.

Rick
 

HPwannabe

Seaman
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Rick, thanks. I get the idea of welding through the hole, but there's hardly room there for the nut itself. It could work though. Here's the other issue - I'm almost certain this is not a stainless bolt. I don't think any of the bolts on the pipe are. This particular bolt might have been put in there by me (this boat has been in my family for a very long time). But I'm pretty sure the rest of them were factory (hard to be sure, been a long time since that pipe was installed). So anyway, the corrosion in there is probably really bad. I have worries about the easy out too. Mainly that even if I get it to go in there, I'll just break it off due to stuckness of the bolt. I have an arc welder but no mig. I think that will work on the plain steel bolt. I'm a little hesitant to weld in there given fire risk, but if I'm careful, I think it's doable.
 

harringtondav

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Wash any gas and oil from you bilge with TSP before welding. You can also buy a couple black carbon fiber fabric heat shields to protect things from spatter. Big box plumbing depts have them around the solder and torches. They work well.

I also use a 'Never Seize' type compound on steel to alum threads.

As far as forcing the pipe loose, see if you can slide a thin washer or shim in the loose flange gap and use it as a fulcrum when forcing the pipe upward/rearward. I've also cut thin oak wedges to help persuade things apart.
 

HPwannabe

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Messages
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Wash any gas and oil from you bilge with TSP before welding. You can also buy a couple black carbon fiber fabric heat shields to protect things from spatter. Big box plumbing depts have them around the solder and torches. They work well.

I also use a 'Never Seize' type compound on steel to alum threads.

As far as forcing the pipe loose, see if you can slide a thin washer or shim in the loose flange gap and use it as a fulcrum when forcing the pipe upward/rearward. I've also cut thin oak wedges to help persuade things apart.

I had essentially the same thoughts, considering how to get some leverage on the thing. One other consideration is this. Somewhere in this thing there is a leak (most of the reason I took the engine out and started this is due to water coming in the boat). I'm pretty sure there's a hole in there somewhere (a big salt blob was all around it). So maybe first step is to clean it up really good and see if I can find the hole. If it turns out that the Y adapter itself is corroded through, then what the heck, I'll just cut it out. The riser parts of the assembly look okay. But I haven't really tried to inspect it real closely yet. It could be leaking at some other point in the assembly.

There's some back story to this. A few years ago I had a mishap in which the boat rolled off the back of the trailer, while on the ramp, and landed on the stern drive. It didn't appear to damage anything obvious that could be seen, but I've always wondered if there might be some damage hiding somewhere. I think I might have found some. The inner transom plate appears to have cracked. The bottom portion of it seems to be loose, flopping around by itself down there. I can't help but wonder if that wasn't caused by the sterndrive sustaining extreme pressure from the accident. That may have also had something to do with the leak. Whether it's just corrosion, or some joint that got stressed, or even a crack, don't know yet.

Thanks for your suggestions.
 

harringtondav

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Good additional info HPwannabe . I don't know the Gen I, but am knowledgeable on the Gen II. ...thinking the transom assemblies are similar. That whack and loose transom plate are red flags. Hopefully your boat's transom is solid. I'm assuming your salt blob is around the Y pipe flange joint. You'll need to get that Y pipe off, and dig deeper.

The Gen II Y tube flange is integral with the outer gimbal housing. The inner transom plate is a clamping structure to hold the two together, and support the engine and steering system. The loose bottom section of the transom plate isn't supporting the outer gimbal assy. This is probably causing flexing that's stressing the the Y tube joint, as well as your gimbal bearing alignment. Best action is to repair by welding or replacement of your transom plate.

If the crack is above the bottom studs, but no higher, you may sneak by torquing up the bottom studs to stabilize the assy. Under power the top of the assy pulls aft, bottom pushes forward. Reverse or a hard power off creates the opposite forces. But if the crack is above the second pair of studs you'll need to fix your transom plate. The flexing may take out your gimbal bearing and engine coupler as well.
 

HPwannabe

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harringtondav I think there is "some of everything" going on here. I hope to have some time tomorrow to dig deeper. But from what I can see, the crack is right across, or just below, the two lower bolts. So the part below that is the very bottom part of the bracket, and it's sort of just sitting there, completely loose. The pressure from the accident would have pulled those bolts outward - and it makes sense that that could have cleaved the lower part of the bracket right off. This would have been aggravated by a condition like a soggy transom. This is a very old boat, and I'm sure the transom has gone soft at the bottom (I can tell by just tapping on it). It's an early fiberglass hull (1966), very good quality, but time takes its toll. So, enough force on that stern drive could have just compressed the transom and broken the plate. If I can find one, my plan is to replace the plate. The salt blob was all on one side of the pipe. Hard to tell if it's the joint or just a hole rusted in there. I'll keep you posted on what I find.
 

GA_Boater

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Why don't you just pull the rest of the hardware, the transom plate is busted already and can't be welded in place anyway. Then you can work on the Y pipe too.
 

HPwannabe

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Why don't you just pull the rest of the hardware, the transom plate is busted already and can't be welded in place anyway. Then you can work on the Y pipe too.

At this point, I'm sure I'll probably wind up removing all the hardware. Since I have to pull the plate, I might as well then remove the gimbal housing, inspect everything thoroughly, replace what's broken, etc. But I still have to get this stupid stuck bolt out. I don't have the uppers removed from the y pipe, so I can't pull the plate/housing off yet. And I'd rather not try to disassemble the pipe with it in the boat if I don't have to. I'm thinking those bolts might by stuck too, and they'll be easier to manage with it out. But if that y adapter itself is already shot, it doesn't matter much. So that's first order of business - find out if I can just destroy that. If that's the case then I don't have to be careful with it.
 

Bondo

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I have first gen alpha and trying to remove Y pipe.
I don't have the uppers removed from the y pipe, so I can't pull the plate/housing off yet. And I'd rather not try to disassemble the pipe with it in the boat if I don't have to. I'm thinking those bolts might by stuck too,

Ayuh,..... There hasn't been a multi-piece y-pipe since back with the old MC-1 drives,........

Yet you say you have an Alpha 1,..??..??
 

HPwannabe

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Feb 15, 2020
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Correct, I used sloppy references. It does have an alpha drive, but the gimbal housing and all the transom hardware is pre alpha. I did finally get the thing out of there. After it was clear that the y adapter was shot, I just cut the "arms" of it off, right at the junction, so I could pull it out with the gimbal hsg. The y adapter was toast. I can't believe it wasn't leaking any worse than it was. The theory of the damage due to the accident is probably correct, at least as far as damage to the inner plate. In other words, the transom is also shot up to about a foot above the bilge level. Now got to figure out how deep I want to go into that. But I don't know if the y pipe failure was related. Hard to tell. The other great news is that there is also damage on the gimbal housing of course, where the pipe connects - corrosion got to the area around one of the small lower holes. Pretty sure this is irreparable. I'm trying to paste a picture, not sure if it will work. Looks like I'm in for a fairly thorough rebuild, including transom work.
 

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HPwannabe

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achris, glad you asked. Because I am now in the hunt for new hardware. The unit I have is MC-1, apparently around 1976. This unit came with a 165 hp inline six GM. Later we installed a 350 V8. I know, the gear ratios are not right in that sterndrive for a v8, but we later replaced the stern drive with a first gen alpha with 1.5. So my question now is, will the R/MR gimbal housings that were made between the MC-1 and the first actual Alpha be a direct swap? From what I can see the only obvious difference is a redesign of the gimbal ring - these have the two bolts at the top, and the revised trim position sensor/hingepin setup. Importantly, the exhaust connection looks identical. If this won't cause a problem, are there any other issues like bolt spacing through the stern?
Thanks!
 

Bondo

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Ayuh,..... Jump all the way to the Alpha 1,.......

You'll need the Alpha 1 flywheel cover for the motor though,.....
 

achris

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Depends on which MC-1 transom assembly you have. The earlier ones had the trim limit switch up above the bell housing, and the trim position sender was on the inner transom plate, as part of the hydraulic system. The later MC-1's have the trim limit and trim position sensors on the hinge pins (either side of the bell housing).

If you have the earlier assembly, you need to slightly open out the centre section of the cutout and relocate 2 of the centre stud holes. (from memory, they moved down about 1"). This is not a difficult job. If you already have the MC-1 transom assembly with the hinge pin senders, a later (R, MR, Alpha One) assembly will slip straight in. There's absolutely no difference between the R, MR and Alpha One transom assemblies. They are all identical. Even with the later MC-1 housing, the only difference is the bell housing. Change that to a the later style and no-one would know the difference. One thing that did change quite a bit was the trim rams.

The 2 very top studs didn't appear until the Gen II (1991 and later), and they are completely incompatible with a MC-1 to Alpha drive.

The ratio difference between the 165 (1.65:1) and the V8 (1.5:1) is in your favour with just a prop change to a slightly higher pitch. Replacing it with a 1.5 ratio drive wasn't really necessary...

Hope this helps.

Chris.....
 

achris

More fish than mountain goat
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Ayuh,..... Jump all the way to the Alpha 1,.......

You'll need the Alpha 1 flywheel cover for the motor though,.....

If it's the earlier MC-1, yes, but I suspect (haven't tried it, but all the calculations say) the later MC-1 inner plate (and thus flywheel cover) will fit onto a later (R, MR, Alpha One) gimbal housing. The stud pattern and cutout are the same...

Chris.....
 
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