Completely seized nut on engine mount

[stnick]

To lift a engine a couple of inches to remobe the mounts ! Deflate a basket ball place under the engine get a compressor and blow up the ball slowly . Loosen all the mounts remove all the mount nuts . The engine will slowly rize 4 inches above the old mounts. Enough to remove and replace all the mounts.
All the best

[JOHNMARDALL]

And the effect of the heat on the rubber in the mount?

[hellosailor]

"and I'm hesitant to use PB blaster as I believe it will damage the rubber in the mount?"
Slathering the rubber up with grease or wax will keep solvents off it, but there's something else to consider.
All the rubber makers (Goodyear, Gates, pick a name) tend to say that engine mounts should be REPLACED WHEN FIVE YEARS OLD because the rubber (or other elastomer) tends to oxidize, stiffen, and break down from the heat and vibration. If PBlaster or anything else happened to make that breakdown obvious...well, yeah, it is past time to change the entire engine mount in any case.
Something we all ignore but really...once you're going there...

[Jim Cate]

Seems like you haven't tried the Reducteur H-75 yet, have you? If you had, very likely you would not still be reading this thread, for the problem would have been solved.

However, I agree that replacing all the mounts would be a good idea.

Jim

[bongo]

I've got the same issue with one motor mount on my Westerbeke 40. I also happen to be somewhat of an expert at getting rusty stubborn fittings apart, (merchant marine engineer 35+years). In this case, none of them have worked. PB Blaster, Kroil, acetone/auto tranny fluid, Bees Wax, the "heat" wrench, 6 sided sockets with breaker bars, cheaters, and big hammers... Sometimes this happens, then we either drill or cut, or use oxy-acetylene and cut or blow the bolt/nut out of there. Of course that is easy on a steel ship, but not so easy adjacent to fiberglass bilges/stringers. In my case the temporary fix: that one mount happens to be frozen in just the right place, so I was able to align the propeller shaft flanges with the other 3 motor mounts. Long term, I'm replacing them all. Luckily they are relatively accessible.
I tend to lift machinery from overhead too. Wire slings/turnbuckles/come-alongs ...but I have also used jacks and wedges...when applicable.
Best of Luck.

[OkiMike]

Yeah, I used a Milwaukee sawzall with a Torch blade for thick metal on my stuck exhaust flange screws. PB Blaster helped removed rust but didn't do anything for the bolts that were, for all intents and purposes, welded together through heat and rust over the years.

[Nicholson58]

Originally Posted by matthidinger

Unfortunately the PO let the heat exchanger drip seawater on the starboard engine mount for years. I can feel the washer below has some wiggle room and the engine vibrates more than I believe it should. So it's due for an alignment.

But first I need to get the nut off.

I don't own a torch or have any real way to apply intense heat, and I'm hesitant to use PB blaster as I believe it will damage the rubber in the mount? Would a nut splitter like this have some success? Unfortunately I already paid a mechanic to fix this last season and he couldn't get it to budge (and left me with the $500 bill). Really trying to minimize any further cost here, but I understand engine alignment is very important.

https://www.amazon.com/Teng-Tools-Pi...gateway&sr=8-6

Do you really need it off?

When all of the other methods fail, use a die grinder with carbide burr to totally cut the bolt. Replace the rubber mount. Keep a strong magnet near the cutting to pick up the chips. A saws-all might work too.

The die grinder carefully applied might let you cut the nut alone. The stud on th mount is probably in bad shape.

[George DuBose]

I would use a Dremel with a cutting disc to split the nut. Shouldn't take more than 10 minutes.

[Dsanduril]

Originally Posted by matthidinger

T... I'm a little lost on where the use the feeler gauges to adjust the engine alignment though.

A little surprised no one has answered on this next step of your task. The traditional method is to loosen the bolts (!) holding the shaft coupling to the transmission output. Then you insert the feeler gauge between the shaft coupling and the transmission flange. Measure left/right/top/bottom and then adjust engine mounts to make all gaps the same. It can be a long, drawn-out process.

YouTube and Google are your friends (try "aligning marine diesel engine"), as there are lots nuances, tips, tricks, and favorite methods.

[Juggerknot]

[QUOTE=matthidinger;2853792]Unfortunately the PO let the heat exchanger drip seawater on the starboard engine mount for years. I can feel the washer below has some wiggle room and the engine vibrates more than I believe it should. So it's due for an alignment.

But first I need to get the nut off.

I don't own a torch or have any real way to apply intense heat, and I'm hesitant to use PB blaster as I believe it will damage the rubber in the mount? Would a nut splitter like this have some success? Unfortunately I already paid a mechanic to fix this last season and he couldn't get it to budge (and left me with the $500 bill). Really trying to minimize any further cost here, but I understand engine alignment is very important.

https://www.amazon.com/Teng-Tools-Pi...gateway&sr=8-6[/QUO

Time for new motor mounts, cry now or cry later.

[nilespf]

My apologies if already suggested but the pic seems to indicate a few more bolts and the mount can be removed from the engine AND the boat assuming those bolts and nuts aren't frozen as well. To get the bond between the two layers of metal to release----- probably can only be accomplished with heat. Another idea is if you have an impact driver. Just may be able to get high enough on the torque curve to break it free.


PN

[thruska]

Originally Posted by matthidinger

Unfortunately the PO let the heat exchanger drip seawater on the starboard engine mount for years. I can feel the washer below has some wiggle room and the engine vibrates more than I believe it should. So it's due for an alignment.

But first I need to get the nut off.

I don't own a torch or have any real way to apply intense heat, and I'm hesitant to use PB blaster as I believe it will damage the rubber in the mount? Would a nut splitter like this have some success? Unfortunately I already paid a mechanic to fix this last season and he couldn't get it to budge (and left me with the $500 bill). Really trying to minimize any further cost here, but I understand engine alignment is very important.

https://www.amazon.com/Teng-Tools-Pi...gateway&sr=8-6

Get the lowlife mechanic back to do it right. If y’all deal with fly by nights, you write your own contract tgat they sign , not the other way around.
After your done screwing around with wrecking it , just replace the motrmount completely, thr hull rail probably needs attention by now...,
What does the other mount look like ?
Good luck

[roberttigar]

Had exactly ther same problem. Its a tight area to work in and while heat may dfo it torches scare the hell out of me. So I decided to cut the nut off uning a dremel with a cutting blade. Didnt even get 1/2 way thru it. The cutting blade generated enough heat to brake the rust free. Took it off with a wrench. Bob

[fish53]

Just remove the mount from the side of the block and the beds then you can put it in a vise and work on it in comfort, support the engine properly. I would caution against Bushing inc. mounts, they're junk, R&D are better and cost the same. You should be checking alignment at least annually, I use PetroWrap, a wax impregnated tape, to pack around anything like this that I want to protect from corrosion, ferrous metals on boats need protection.