jimbos'ss

iTrader: (6)

I was torquing the little 10mm head bolts to 22ft/lbs when one snapped. So I pulled the head off and went to extract the bolt and it was barely tighter than finger tight coming out. Is it common for the GM TTY head bolts to snap like that??? Maybe a defective one? Kinda baffled on that one, luckily a buddy has a spare set of bolts and gaskets laying around. I'm not gonna lie when it snapped all the worst thoughts went through my head

thunderstruck507

iTrader: (18)

You weren't reusing the bolt I hope. If you were then I'm not surprised. There's a reason they are supposed to be thrown away.

jimbos'ss

iTrader: (6)

nope brand new sets, I'm pretty **** about doing things right the first time.

TXsilverado

iTrader: (18)

i reuse the small bolts on the inside of the heads. they are not TTY, an i have never had one snap.

jimbos'ss

iTrader: (6)

I never reuse them just in case.

Darkman

iTrader: (2)

Check the calibration on your torque wrench.

Paul Bell

iTrader: (9)

That's good to hear. So many get it right the third time around.

I think you just had a fluke bad bolt. Good thing it went now not in use.

I'd recommend stepping up to ARP bolts. You'll sleep better, especially after this happened.

badazz81z28

iTrader: (6)

I agree, you must have over exerted the torque wrench and didnt notice or Calibration is off. Those bolts are not TTY and 22ft lbs shouldnt snap a grade 10.9 bolt.

got milk??

iTrader: (18)

My money is on a defective bolt. Even if your wrench was defective I know for a fact your not breaking that bolt at 44 ft lbs let alone 22....

89 formula350

iTrader: (8)

you do know gm updated the service info years ago to replace them right?





also make sure you have the hole clean specifically of any fluids. I'm betting it was a bad bolt but it doesn't take much twisting force to snap the shank when the bottom is hydro-locked. just something to keep in mind

Fade2blk500

iTrader: (18)

Make sure that bolt hole is completely dry.. Other than that it was probably a bad bolt. I'd get new bolts and put it back together, should be fine.

msydow

the reason it was finger tight when you pulled the head was because the tension from the bolt head on the cylinder head was gone.

jimbos'ss

iTrader: (6)

I am definitely taking it in, can't trust it right now until it's verified.
If it was my car I would probably upgrade after this, but i'm doing the install for a friend so that's his call.

I have a process for the bolt holes starting with a shop vac with a pencil tube extension and then clean the threads so I'm pretty sure that wasn't the issue.

Once I get the torque wrench calibration verified i'll have a more definitive answer.

TXsilverado

iTrader: (18)

if that's the case, why doesnt GM include those small bolts in their head bolt kits?

wildcamaro

iTrader: (15)

Yea probably hydro locked the bolt that's why it snapped...

mark21742

I had a new stock head bolt snap on mine one time (one of the big ones). It snapped before I was even close to torque.....sucks, but defective parts happen.

I got lucky and it spun right out easily with an extractor

Paul Bell

iTrader: (9)

Interesting panda TX. I can do that.

42273

iTrader: (3)

i think that's a skunk...! i think the threads would have pulled out before the bolt would break if over torqued ? any how ,good news that it can be resolved easily

jimbos'ss

iTrader: (6)

Yah I figure it was just a fluke, I've been using nothing but GM TTY bolts for years.

King Nothing

iTrader: (9)

i did that once, luckily it was #10 so we pulled the manifold and backed it out but yes if you put too much torque on them they will snap. get your torque wrench checked but more importantly don't use a torque wrench on your intake manifold bolts. do them in sequence then get them snug plus 1/4 turn and you'll be good and wont break more bolts