Lost a bolt - having trouble finding replacement

[Kens1990K2500]

I am in the process of replacing my electrical ground straps. When I was removing the ground strap that goes from the firewall (just under the heater hoses) to the back of the passenger side cylinder head, I dropped the bolt holding the ground strap to the engine. Unfortunately, it did not fall on the ground, but got lost somewhere behind the engine. I tried fishing around with my fingers and a magnetic pick up tool, but coudn't find it, no less than retrieve it. At this point, I am resigned to just getting another bolt, but I have no idea the bolt diameter/length/thread pitch. All I remember is that the bolt head was 14 mm.

I went to the hardware store and got an M12 bolt, but it felt too big. I tried a body/fender bolt, but it felt too small. It's a very tight area and I can't put eyes on it; have to go by feel only. Even with the distributor cap off (to replace the ICM), it's very hard to get your hand back there because you are fighting wire harnesses.

Can anybody tell me what the correct specs are for this bolt?

Thanks,

Ken

 

[Supercharged111]

The bolt in the back of the head is a 3/8 16 NC, go with 1/2" or 3/4" long. No ****** fasteners in the engine!

Christ on a *******, c0mm!3 is blocked too?

And so is cr@ck3r!!!!! But Christ is OK. That makes sense.

 

[east302]

The bolt in the back of the head is a 3/8 16 NC, go with 1/2" or 3/4" long. No ****** fasteners in the engine!

Christ on a *******, c0mm!3 is blocked too?

And so is cr@ck3r!!!!! But Christ is OK. That makes sense.

Lol, just got done messing with this same stupid stud and nut on mine and broke a wire in the process.

Maybe “cheese and crackers” works in a pinch?

To the OP, you’ll find that lost bolt on the driveway once you’re done putting it all back together.

 

[Kens1990K2500]

The bolt in the back of the head is a 3/8 16 NC, go with 1/2" or 3/4" long. No ****** fasteners in the engine!

Christ on a *******, c0mm!3 is blocked too?

And so is cr@ck3r!!!!! But Christ is OK. That makes sense.

Ah, no wonder I was going crazy, trying to find the right metric size!

(When did certain words start getting censored around here? Just curious)

 

[Kens1990K2500]

Lol, just got done messing with this same stupid stud and nut on mine and broke a wire in the process.

Maybe “cheese and crackers” works in a pinch?

East302, are you referring to the stud/nut near the heater hoses? I had an issue removing that nut (which is a 10mm). After spraying it with Kroil (awesome stuff), I got the nut turning, and backed it most of the way out. When it got to the end, it just kept spinning. I looked closer, and the end of the stud was a rust blob, instead of threads.

I ended up getting a Dremel with a small cutoff wheel, and cutting the rusted end of the stud off. This was very nerve-wracking, given the stud is very close to the heater hoses. But no mishaps. Fortunately, the stud is fairly long, so still plenty of thread left.

 

[east302]

Mine is a 98 (so it’s probably the same but different if that makes any sense) but it has that stud on the back passenger head for two ground wires. One is a braided cable to the frame, the other a small wire with an eyelet from the harness. The eyelet broke off when my ratchet hit it. Couldn’t see a thing in the process except for the suddenly stray wire popping up.

It’s always the little piddling things that take up a lot of time, but I didn’t have the rust blob so I think I got off easy compared to yours.

For future reference, this site has the old parts diagrams and GM part numbers. You can’t buy anything from them but it’s handy to have when tracking down these sorts of things.

Spare parts catalog Chevrolet EPC Online > nemigaparts.com

Parts catalogs. Spare parts catalog Chevrolet EPC Online.

nemigaparts.com