03 DF140 setback

[Lunchmoney]

Hit a snag last night. Trying to get the power unit off the engine holder and wrung the head off a bolt. It's one of the long bolts too that goes from the oil pan, through the engine holder into the block. I'm pretty certain it is corroded in the oil pan part directly above where the head snapped off. All other bolts came out pretty easily. This one is on the port side right by the exhaust. Any ideas? I was thinking about if I could break that corrosion bond where the bolt shaft passes through the lip of the oil pan, I might could still lift the engine off bringing the bolt with it. Damn the salt life.

[artdf175]

I would suggest a small extraction bit
I had trouble with some of the head bolts a couple of years ago
the small extraction bit got a couple where the heads twisted off, out quite easily.
spray with good penetrating oil overnight first, will definitely help
Art..

[catacom225]

Hi Lunchmoney! Are you saying that only the head snapped off, If that's the case, as art said apply some penetrating fluid also a little heat to draw it up and the block should pry away from the engine holder taking the broken stud with it

[Lunchmoney]

Yes it wrung off right at the head. The entire bolt shaft is intact and stove up (I think) in the top lip of the oil pan and the bottom lip of the engine holder, That area is about 1.125" thick or about 28mm. As the bolt passes through the engine holder, it goes through a clearance hole and as I recall from working on the starboard engine, there's a fair amount of clearance. The female threads are only in the block.
The problem with penetrating spray is the bolt points up so the spray tends to run down and not sit on the area is needs to to work. Do you think some heat will pull the penetrant upwards into the corroded area?
I've never had any luck with screw extractors.
I'm looking at it this way... the corrosion bond is so solid around the bolt shaft in the oil pan / engine holder lips that the head wrung off before it would break loose.

My plan of attack is this...
attach chain hoist to eye so I have some upward pulling tension.
Have a guy pry up on the block from the front, prying against the swivel bracket.
Have a guy prying between the engine holder and the oil pump gear (GENTLY!)
Run 2 or 3 of the 10x160 bolts back in on each side and thread them about 3/4-7/8 of the way in. Tap on those bolts with a hammer. This energy should directly push the block upwards. I won't hit these bolts too hard as I don't want to damage the threads in the block but I think they could take quite a bit of impact before that happens, if they are threaded almost all the way in.
Apply heat to the area where the head wrung off.
Use a large flat tip punch and hit the shaft of the broken bolt upwards.
This is crazy I know and i'll need 5 buddies to make it all happen. But between the upward prying from the front and rear, the upward tension from the hoist, heat on the stove up area, and trying to push the block up by hitting the bolts that are partially threaded in and whacking the shaft of the broken bolt with a punch, I'll effectively be applying a lot of upward force that's distributed somewhat evenly.
If I can just break it loose, I think I can pry the block from the engine holder and pull the broken stud out with it. Once out, I can put a pipe wrench on the stud and likely remove it.
I'm all ears for any more suggestions.
Thanks guys.

[catacom225]

Lunchmoney! you seem to have a plan, But before you screw up everybody's weekend, try hanging it up from your chain hoist and give it a shake

[Solarman]

I've found those bolts to be the most difficult to extract. Because it is not the threads, but the corrosion packed around the shaft that caused the head to twist off, meaning it is very tight!

If you can't turn the motor (up-side down) to get penetrant to soak downward with a little heat to loosen that corrosion, then you'll be beating, prying, and hoisting for a week. There is no reason to damage all the other threaded holes by hammering on them, leave them alone. Up-side down with a good punch, penetrant (plus heating that area around the bolt shaft - not hot) is, your best approach.

If you have a good concrete hammer-drill, and can put a punch in it, so the punch will spin freely, but the constant repeated hammering impact on the bolt shaft, if up-side down, might do wonders.

Be careful prying, don't need to damage mating surfaces, or break something else.

There is no easy out for this job. Good luck. Be patient. Post back how it's going.

[Lunchmoney]

Thanks for the suggestions. I'm going to put the hoist to it and see if it'll shake loose but I don't have much hope there. I do have a good Bosch hammer drill that I can get a punch tip for and hammer on it that way. In order to get it upside down to facilitate the penetrant working, I'd just unbolt it from the transom and pull the whole engine. Then flip it over and hang it by the LU I guess. I'm concerned I'll break a bolt if I try to separate it at the joint between the oil pan and driveshaft housing. Or I could just loosen the upper and lower motor mounts and pull it off there. Hmmm... I'll study on it some more. Good suggestions guys, much appreciated.

[wilbur1]

If you have room? An Air Chisel with a blunt tip will drive it out. And the vibration will loosen the corrosion.

[Lunchmoney]

Got the powerhead off but the bolt stayed and took a chunk of the block with it.
It might can be welded. Wish I would have removed the motor and put an air hammer to it while hanging upside down. That might have gotten it loose. Maybe.

[artdf175]

I don't mean this to sound rather blunt but what was wrong with trying an extraction bit before you break something?
I have had great success with these little tools
The stainless bolts and screws are much softer metal and heads will twist off

Most recently the lower unit oil drain plug screw. There was nothing that would break it loose. Finally the slot was totally gone. Even softer as it appears to be made of a bronze alloy
The extraction tool was the about the only option left and easily did the job
Art

[Horsedoc]

Same Bolt!

I took the powerhead off of my '07 DF140 last week and had trouble with the same bolt. I had read about broken bolts and blocks and was determined not to break anything.
I used a low power electric impact wrench and worked forward and backward on the bolt for a good long while until it finally broke loose. Lots of white powder came out of the hole.
My plan is to go back into that hole with a new bolt and pack it full of grease to hopefully prevent that problem in the future.
Should I treat them all? Any down side to packing those holes with grease?
I am dealing with some minor corrosion due to salt water in the oil. Haven't found the leak yet. Sending the head and block to the machine shop for a checkup. Any advice would be appreciated.

Thanks!

[artdf175]

I don't know of any downside to putting marine grease on the bolts. I do this as my engine spends more time in salt water vs fresh
There are also some silicone type lubricants/sealants much like Vaseline
Maybe there is a mechanic that can advise the plus and minus of doing this
Art

[Lunchmoney]

I don't mean this to sound rather blunt but what was wrong with trying an extraction bit before you break something?
I have had great success with these little tools
The stainless bolts and screws are much softer metal and heads will twist off

Most recently the lower unit oil drain plug screw. There was nothing that would break it loose. Finally the slot was totally gone. Even softer as it appears to be made of a bronze alloy
The extraction tool was the about the only option left and easily did the job
Art

Art,
The last one I used snapped off and I had a heck of a time getting it out plus the bolt it was broken off in. Drilling it out straight to accomodate the extractor bit would be extremely difficult considering the proximity of it. Nothing aside from carbide that I've found will drill into one after it's snapped off. Cobalt drills into stainless pretty easily but it's got nothing for the hardened metal used to make easy-outs. They have their place but trying to use one to remove a 160mm bolt that's torqued in plus corroded around the shaft so severely that the head wrung off, isn't practical IMO. I was scared of breaking it off and compounding my problem basically. I'm no machinist or mechanic so my opinion isn't much!
Thanks

[yetibreti]

I have exactly the same issue as Lunchmoney had. head snapped off. Shaft visibly surrounded by corrosion all the way through (a good 100mm area up through the hole) I have to agree with Lunchmoney on the prospects of drilling the tip of the bolt (where the head broke off) and using a bolt extractor. Its proximity is just too difficult to drill, and the corrosion too strong, as all i have is basic easy outs. I think my next step is turning the engine upside down, so i can pour penetrating oil in the hole, and then get a hammer drill on the end of the broken bolt to try and shake loose the corrosion. Does anyone know if heat will help? And if so, what type of temp? I only have a hair dryer!!

[computertamer]

Bringing this thread back because I have the exact same issue! Snapped the head off of the long bolt next to the plug hole in the engine holder. It's broken off about 1/4" below flush, so I can't get very much penetrating oil in there to soak.

I've tried lifting the powerhead off to the point of lifting the stern of the boat off of the trailer bunks! No go. Then I removed the powerhead/engine holder/oil pan assembly from the bracket and it's currently hanging upside down from an engine hoist with chain wrapped around the engine holder/oil pan.

I've tried torching the surrounding area with map gas and hammering the broken bolt, using another bolt as a driving rod, while the engine is hanging upside-down, hoping that the weight of the powerhead along with the hammering would break the corroded bolt shaft free. No luck!

Any other ideas would be greatly appreciated!