Topic: M10 front engine hanger bolt removal

[Cevan]

I am trying to remove the m10 bolt that attaches the top engine case to the hanger (photo below).  As you can see, the nut is captured in the aluminum engine case (why Honda???).  The right side came out easily but the left side bolt is in there good.  I've tried heat but I'm afraid that heating that area too much will cause the aluminum to break before the nut comes loose. 

Should I just leave it be?  Any advice is much appreciated.

[newday777]

Is it that you can't get the bolt loose from the nut or is the bolt frozen to the aluminum case?
Did you use Kroil or PB Blaster on it to help break the corrosion that happens?
Heat won't be a problem on that.

[MauiK3]

Try soaking with penetrating oil, it should be ok to apply a little heat to the side of the nut, be careful to not start a fire with the oil. If you have an impact wrench that should help get it moving. Otherwise, a long breaker bar may work. Don't apply heat to the aluminum. It's likely some corrosion, maybe even inside the hole so soaking for some time may loosen things up some.
If all else fails, get a small die grinder (Dremel type tool) and a small carbide burr, grind a groove all the way through the side of the nut as far as you can and hit it with a chisel to split it some. Of course stay away from the aluminum. Drastic sounding but doable. You can find a Christmas tree shaped burr that will let you get close to the case without grinding it.

[MauiK3]

Also, show us the head of the bolt.

[Cevan]

Pic of head of the bolt.  I have an impact so I'll start with that on a low setting.  My fear is breaking the aluminum case.  I've been hitting it with PB Blaster every few days for awhile now. 

[Rookster]

Cut the head of the bolt off then drive the shaft of the bolt and nut out with a drift.  The triangle bracket gives you a nice sacrificial surface to cut or drill next to.  You can pick those brackets up on ebay for about $20.  If you are neat then you might not need to replace the bracket.   

Scott

[BenelliSEI]

As a last resort, use a small cutting wheel in a Dremel and cut a slot in the nut. Then use a sharp cold chisel to split the nut open?

[scottly]

Should I just leave it be?

That would be the safest and easiest option.

[madmtnmotors]

Is the nut spinning with the bolt, or is the bolt seized?

[Cevan]

Is the nut spinning with the bolt, or is the bolt seized?

Oh god no, the nut is not spinning.  That would be catastrophic.  I'm just afraid of using too much force and snapping the aluminum that is capturing the nut.

Update: I just cut the head of the bolt off.  Safest option in my opinion.   Easy to source a new bolt versus a cracked case.