You Know it is going to be a $hitty day when you find this

[Lou]

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From Here.

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How Nice!

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And your drill bit walks and does this!

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But patience (and plenty of 4 letter words) paid off. Initially left the clamp on to use as a guide for drilling the stainless bolt and hoping not to break the seal on the exhaust manifold. Was also hoping to use an easy out, but that did not work either. After having visions of a broken easy out in a stainless bolt, gave up on that train of thought.

After removing the other bolt (lucky it came out) removed the clamp and initially got the bolt to turn 1/8 turn with a punch, then it jammed. Interesting to find the upper bolt thread goes right through into the cylinder head exhaust port. So the rest was removed by more drilling (and cursing) and finally much work with a small chisel.

Amazingly did not damage the threads and ran a tap into both holes before reassembly using grade 8 STEEL bolts. Big surprise is it did not leak, even after a 60 mile trip in the woods! This manifold has the gasket underneath it. Believe the broken bolt was caught before driving the mutt, because I am pretty sure that gasket would have blown out without the bolt there, lucky find!

I am no expert at drilling out broken bolts (see photos, lol) but managed to get it done without hurting anything. But I would rather take out and reinstall the power pack 5 times then deal with broken bolts! Great news is there are 2 more (not counting intake manifold bolts) ready to break some time in the future!

So what is the general consensus here, wait until they break? Try to remove them and hope they don't break? Or drive the Mutt to Ricks house and watch him curse and deal with it, lol

[Lou]

Proof it was fixed, lol.

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[rickf]

They were the easy ones in the front. The ones in the back are the harder ones to drill since there is always something to prevent the drill from being straight. The fact that is it thread galling and not rust that causes this problem it really does not matter whether you do the other now or later, they will either come out or they will not and extra time is not going to change anything one way or the other. I would just wait until you plan on having it down for a while for other work.

[m3a1]

Agreed. Choose your battles. May come the day when the power pack needs to come out and then at least you'll be on a more level playing field. Meanwhile, pretend it's not an issue.

At one time there was an interesting video on YouTube that showed a guy running a new stainless steel nut up and down on a new stainless steel bolt. it galled up rather quickly and became stuck. Stainless steel is NOT your friend.

Cheers,
TJ

[Lou]

What is the old saying “Don’t fix it if it isn't broke”. Well broke that rule today. Decided to replace the rear exhaust manifold bolts today. They were not broke, but after the earlier fiasco of drilling a broken one out decided to go for it.

Top one came right out (soaked them with pb blaster hours before we started) the bottom one started galling after one turn. Had to keep resisting the urge to use the impact gun on it. Just put a breaker bar on the bolt and kept working it back and forth while spraying the bolt with pb blaster. After half an hour was getting nowhere and tried the transmission oil and acetone treatment, that seemed to make more progress.

Really wanted to use the torch to heat up the cylinder head but feared it would ruin the exhaust manifold gasket. So started using a heat gun. After using it the second time (leaving it there a long time while inhaling the lovely aroma of burnt transmission fluid) progress was made. Still cannot believe a heat gun can do this, always used a torch.

Anyway, was amazed the stainless bolt was not galled but the threads in the cylinder head were. Chased the threads with a tap and all was well and it did not leak after putting it back together.

Noticed the other bolts under the intake manifold (which also hold on the exhaust manifold) were NOT stainless. They were steel and slightly rusty.

Figured since they were steel (and a pain in the ass to get to) to just leave them alone. What do you folks think, would you change them? Is it only the stainless ones that break for no reason?

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[rickf]

The stainless steel is soft and the threads gall and turn into fishhooks when you tighten them. That is why you can't get them out. For future reference oil is better than solvent in this case, you want to lubricate those threads and PB is a solvent, not an oil. Light machine oil like 3 in one oil. The steel bolts will be fine, leave them alone until you have to remove the manifold. You can get to the back of them to spray them with PB. Personally I use Kroil and now I plan to use Silikroil which has a lubricant in it and it does not dry out like most of them do.

One of the biggest problems with those stainless bolts is that nobody looks at the torque specs before tightening them. It is actually very light, 18 ft.lbs. springs to mind but I would have to look it up. They are much lighter than a standard 3/8 bolt would normally be. The main reason is because if you tighten them past that you will crush the thin exhaust manifold but I suspect the stainless bolts have something to do with it. I have never figured out why they even used the stainless when regular steel bolts worked just fine on exhaust manifolds for 60 years prior. Surely some engineer had to have enough smarts to know this was a problem?!

[Hambone]

I had to deal with that a couple months ago, my bolt wasn't stainless but it wouldn't budge with easy out or LH bit. I got lucky as my initial drilling was luckily in the center, when I tapped it the old threads can out like a slinky, I got lucky on that for sure.

[rickf]

Easy outs are nothing more than a tool to jam the treads of a rusted bolt tighter into the hole. Look at how an easy out works, it jams into a hole in the offending bolt and spreads the bolt out making it even tighter in the hole!!! They are worthless, I have not used an easy out in 40 plus years!