Engine mount eyebolt hole stripped

[Tiki2777]

Well I was on my way to getting finished with my head gasket job when I was torquing down the main engine mount eyebolt (timing side into the shock tower) when the bolt got 'loose' on me when I was nearing the proper 67-72 ft-lbs of torque. I pulled the bolt out to find that there were threads left over from the hole riding in the threads grooves on the bolt.....WTF.
Has anyone dealt with a stripped out shock tower engine mount bolt hole before? Please throw me some ideas people, my car is begging to be driven

 

[91-GS]

Probably simplest solutions would be to either re-drill the hole and thread it for larger bolt, or to heli-coil it.
If you can get access to the back side of the panel where threads are an option would be to completely cut out the threaded insert and weld in a new one.

 

[Tiki2777]

Would it be a bad idea to run a longer bolt and throw a nylock-nut on the end?

 

[Lester B]

I wouldn't suggest that.

That connection gets its strength from amount of threads. There isn't enough threads in the nylock, or will it have enough compression.

I discovered one of mine was stripped a couple of weeks ago. So last weekend I went and got a larger drill bit and fine thread tap. Drilled and tapped out the mount above the crank, to the next biggest. Which was a standar size. 7/16x21 I beleive.

Now I'm like WTF didn't I do both sides. Big grade 8 bolt next to stock fastener looks chince.

Next biggest metric size was a big jump and I thought it might be a bit much of metal shards that would snag rather than cut.

Just my two cents man.

Btw, cover the main pulley underneath with a rag to catch cutting fluid and shards.

 

[Lester B]

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