Preferred Method to remove Engine to Deck Bolts w/o breaking

[Seakaye12]

OK....once too many for failed attempts to remove the three mounting bolts that hold an engine onto the deck of a simple cheap rotary mower! They are all too prone to breaking off; at least recently.
I assume that they are put together with loc-tite of some sort.

What's the best procedure? Heat? How much? Other tips and fav techniques?

Thanks Guys!

PS: If you have any suggestions for removing a broken bolt (broken off in the base of the engine...) I imagine there are people on here who would like to know that too

[KE4AVB]

It not Loctite it is that the steel bolt gets stuck after some time because it has fused with the aluminum block through galvanic action. This compounded by the fact that most of these bolts are of the self tapping type. Although this happens slowly and at a very small scale, it is enough over a period of time to seize the bolt permanently. The type seem easier to break is that your probably dealing with cheap Chinese bolts.

There is several ways of doing it and there are several examples on the net. Just Google "removing frozen bolts from aluminum". Of all things its take a lot patience when doing this.

[bobodu]

Heat the bolt with your favorite torch, when still hot-rub a candle on the hole from the top. Let cool a minute or two and work it BOTH WAYS. As the blot heats up...it will expand and break the bond. As the heat transfers to the aluminum, there will come a moment of equilibrium where it will break free. Some people claim to heat AROUND the bolt....but think about blowing up an inner tube.....the hole doesn't get bigger....The wax WILL work down into the threads and lube them up. Thais also work very well on those rusty muffler nipples.
This was known in the old days before political correctness as "The Old Indian Wax Trick".

[38racing]

I have read that dripless candles should not be used .

[NevadaWalrus]

Waxing does work but I preferred to heat the block around the bolt. Aluminum expands more then steel when heated so the hole does grow.

[RoyM]

I have had success zapping the bolt with an arc welder. The bolt gets hot and tries to expand compressing the metal, as it cools the bolt shrinks. Do remember to remove the fuel tank before trying this.

[Skywatcher]

Hi Sea

My preferred method is using a 3/8" air impact wrench. First off, spray some of your favorite penetrating oil into or onto the top side of the bolt hole while unit is sitting on its wheels and let sit for 30 minutes before attempting to remove bolts. Set the wrench for forward as if tightening the bolt and give each bolt a 1 second burst. Next, set to reverse and give a 2 second burst. Repeat process and bolts will start to move. I may take several rounds before you start to see any movement in the bolts but be persistent and you will get results.

This method sometimes works on the spindle housing bolts of lawn tractor mower decks. If the housing is to be replaced, I just use the 1/2" impact to twist the heads off and lose the bolts with the housing. When replacing the bearings, I usually leave the housing in the deck so I don't have to fight with the bolts. All the best,

Sky