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Broken Head bolts, Head is stuck


attworth

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Attempted to remove my head last night. I got all of the bolts loosened in the proper order, except the 2nd to last one, and about the 5th to last one. The 5th to last broke off after turned out quite a ways, and broke just above the threaded part of the bolt. The 2nd to last broke about 1/2" below the bolt head. Took the rest of the bolts out and turns out bolt #4 also broke, above the threads. Didn't feel it or hear it.

 

I attempted to wriggle the head loose from the ends, keeping the head as straight as possible, but it's not budging what-so-ever. I'm assuming that since the 2nd to last bolt broke so close to the top of the head, that portion of the head is still nice and torqued.

 

I didn't want to warp the head any more than it probably already is now. Anybody have any ideas of what I can do to remove the head safely? Currently the camshaft still turns, so that's a good sign - I'd rather keep it that way.

 

I'm a little nervous about drilling out the bolts since aluminum heads are pretty touchy.

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Tony,

You don’t’ have to worry about warping the head any further. You just need to be sure all the bolts are out, or at least the heads of the bolts broken off. :wink:

 

So long as the head of the bolts are no longer attached to the shank of the bolt, there are no more “clamping” loads holding the head down on the block. What you are fighting now is the stuck gasket and the gunk that builds up between the bolts shanks and the bore in the heads for those head bolts which can make it quite difficult to remove the bolt from the head, even after the head is removed the block.

 

Be sure you have removed all 14 head bolts, (or broken them) and don’t forget the two little bolts on the outside of the head, up front that go down into the front cover. :wink: Be sure the timing chain is off the cam gear or remove the cam gear altogether.

 

With that, get as aggressive as you dare in prying, lifting, and rocking the head. Depending on which side of the block the long broken bolt is, that is the side to rock the head towards. Once the head come free, this will probably bend that bolt, but don’t worry about that. If it breaks a little further down, even better for easing head removal. Some strategies are using pry bars/boards under the cam, in ports, etc. Be creative, but also don’t damage or mar any components or machined surfaces you plan to reuse.

 

Once the head is off, you’ll have to contend with broken bolts. I feel your pain here. Not an easy task for a non machine shop equipped wrencher. If you are planning to remove the block and tear it down/rebuild it, just leave those stubborn bolts for the machine shop to contend with. If you are feeling daring here are a few tips that will help.

 

For the broken bolts that protruding above the deck surface enough to grab with a pair of vice grips, smacking the tops of them with a hammer hard, VERY hard, then apply lots of heat to the block surrounding the stubborn busted bolt. Smack the bolt a few more times and work at the bolt with vice grips. Smack some more, apply more heat, repeat. The rapid thermal expansion and shock loading from smacking them is the most successful method for freeing up those stubborn rusty/seized bolts. Feel free to try the penetrating oils, over night soaking, etc. I have found that sometimes helps, but not always. The heat and smacking method is my hands down, most successful method for removing stubborn bolts, pipe plugs etc. If that doesn’t work, then its on to more sophisticated means, drilling, picking out residual bolt threads, and worst case, drilling even more and helicoil/threadsert.

 

Hope that helps,

Paul

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Tony,

 

In the past I have had good luck by inserting a wooden dowel, large enough that it wont break into either the intake / exhaust ports, and using the additional leverage pry the head loose. This way you will not mar the machined surface of the head.

 

Good Luck!

 

Damon

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make sure the 2 little 8mm screws are out that go into the timing chain.

 

wack the side of the head with a rubber pallet. It should lift off easily.

 

you are going to have problems getting the broken bolts out. may end up pulling the block and having a machine shop do it.

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He can't rotate it if the head bolt shafts are still in there.

:lmao: Is that reply meant for a different thread? Who said anything about "rotating" the head?...

Did you see what they were torqued to?? that sounds rediculous. Good luck. [ARP head studs rock :)]

Not sure what that has to do with this issue. If they were under or over torqued, that would not cause the bolts to break in this manner. Head bolts over torqued to point an issue is created, would only over stretch the bolt beyond its yield point allowing the head to relaese its clamp on the gasket resulting in a head that "pops" sooner than it should've. His issue as he described, is actually common with these old cars. In the hundreds of L series heads that I have removed since the late '80's, I have seen this same issue time and again and has nothing to do with the original torque values when the head was installed last. After years of time, heats cycles, yadda ydadda, the bolts rust themselves in the block, and busted bolts is the result as it takes more force to release them from their rusted haven than is required to snap them!

 

 

make sure the 2 little 8mm screws are out that go into the timing chain.

 

wack the side of the head with a rubber pallet. It should lift off easily.

 

you are going to have problems getting the broken bolts out. may end up pulling the block and having a machine shop do it.

 

There are NO 8mm screws in the "timing chain". There are however, two "6mm" x 1.0mm bolts in the front of the head that go into the "timing chain cover", but that was already covered in one of the posts above. :wink:

Edited by BRAAP
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Thanks for making me feel better about prying the head all over the place to get it off. I was scared to mess it up. I'll see what I can do and post my results.

 

As it stands, 11 head bolts are removed, 3 broken, and the two tiny screws came out last week when I took the front cover and oil pan off.

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Some times I will run a screw driver into the middle of the head gasket.

I hate getting an old head off, you worry so much about marring deck surfaces.

Or any surface requiring a gasket.

 

The front cover I've had to beat on within an inch of its life to get off.

It's not a very thick cast aluminum part.

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:lmao: Is that reply meant for a different thread? Who said anything about "rotating" the head?...

 

Not sure what that has to do with this issue. If they were under or over torqued, that would not cause the bolts to break in this manner. Head bolts over torqued to point an issue is created, would only over stretch the bolt beyond its yield point allowing the head to relaese its clamp on the gasket resulting in a head that "pops" sooner than it should've. His issue as he described, is actually common with these old cars. In the hundreds of L series heads that I have removed since the late '80's, I have seen this same issue time and again and has nothing to do with the original torque values when the head was installed last. After years of time, heats cycles, yadda ydadda, the bolts rust themselves in the block, and busted bolts is the result as it takes more force to release them from their rusted haven than is required to snap them!

 

:redface: Geez... I feel a bit sheepish.

 

The torque spec comment was completely daft, I have no defense for that one.

 

The 'rotate' comment - If you try and rotate the head like this with head bolt shafts still in there:

 

L28_2.jpg

 

Then I *assumed* that you wouldn't be able to budge it much, or any at all, but as none of the L28s that I have taken apart have had broken head bolts, this statement was completely unfounded. Please delete it from the thread so it will not show up in the search archives, I will think before posting about things that I don't have experience with next time. Thanks BRAAP

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Its all good, please forgive my brash approach at clarification.

 

For clarifications sake, (your picture is a good one by the way), because all the head bolts broke at the top of the threads, all but one that is, that leaves those bolts just protruding above the deck surface. Now with the one bolt left long, the head will rock/rotate towards the side with the long busted head bolt, (the other busted bolts are low enough, the the head will easily clear them), and will end up "bending" that long head bolt, which is fine, it is no good now any how.

I assumed that I had explained that above, though if I would have been more concise then, it wouldn't have led to this confusion.

 

Again, my apologies. shy.gif

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wack the side of the head with a rubber pallet. It should lift off easily.

 

 

 

Rubber pallet....baow baow baow.....sorry - I couldn't resist!

 

Actually, I find a dead blow urethane hammer works well in this situation. Rubber pallets (mallets) absorb too much of the shock.

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I've had absolutely no luck. I removed all the rocker arms and the cam and towers so as not to damage them.

 

I tried just about everything I could think of and the darn thing just isn't moving. I even beat on the water outlet at the back of the head with a dead blow rubber mallet and no luck. It's not moving whatsoever.

 

It's almost as if there's still a bolt in there somewhere, but I've checked, double checked, counted the number of bolts I took out, and NOTHING.

 

*sigh*

 

:evil:

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You took the front cover off correct? If so put a 2x4 under the cam chain galley hole and start wacking with a big hammmer!! it should lossen up. You might also want to try putting some pb blaster or better yet sea foam deep creep into the holes with broken studs to losen up the grim holding the head to the shaft of the bolt. If your in a pinch i have have a set of turbo head bolts that im replacing. I dont know the history on them but just pay shipping and they are yours. But like others have said. ARP is the way to go. you can get them off ebay for like 140 shipped.

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  • 3 weeks later...

So I finally got the head off. Wood didn't work. Rubber mallet didn't work. Heat didn't help.

 

Finally, after about an hour with a 10lb sledge, and lots of aluminum chunks missing later....

 

Needless to say, the head is ruined. It'll be a good learning example. I'll take it apart and put it back together. It's a pretty paper weight. The good news is, using vice grips and a hammer, the broken head bolts came out pretty easily.

 

My bores look beautiful. Piston rings were in great shape. Crank looks great (no plastigauge, but there weren't any scuffs or odd anomalies.)

bore_thumb.jpg

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Was there any thing holding you up besides the old head gasket?

 

The long bolt was pretty much glued to the hole in the head, and it would not bend for anything. All three bolts were on the same side and next to each other. Once the gasket was broken loose, I carefully pulled it down from the block with an old screwdriver. I tried penetrating fluid (PB Blaster, WD 40 and some other brand,) and heat, nothing would break it loose from its hole.

 

I forgot to mention that I had the motor up-side-down when I did this. Gravity was my friend.

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