Necessary to replace head bolts?
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Necessary to replace head bolts?
I'm doing a head gasket on my 86 runner 22re and I'm wondering if it is necessary to replace the head gasket bolts when replacing the head gasket......
I've read no and yes
the head bolts have 15k miles on them
I've read no and yes
the head bolts have 15k miles on them
#6
I have a big fat copy of the Factory Service Manual. Guess what it says? NO, you DON'T need to replace them.
It marks all the non-reusable parts, and the head bolts are not one of them.
If you think about it, unless you're bottoming out the bolt, a bolt which has had the stretch taken out of it is going to provide MORE clamping force than a stretchy bolt. I think this is why some advocate re-tightening the head bolts after a certain distance.
It marks all the non-reusable parts, and the head bolts are not one of them.
If you think about it, unless you're bottoming out the bolt, a bolt which has had the stretch taken out of it is going to provide MORE clamping force than a stretchy bolt. I think this is why some advocate re-tightening the head bolts after a certain distance.
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with "only" 15k miles on them, I'd say no, they shouldn't need replaced... but then I wonder: why are you pulling the head after 15k miles?
as mentioned, any fastener when exposed to heat and tension, will tend to 'stretch'. some fasteners are designed to handle this, and others are not. generally speaking, any fastener that has been torqued to spec should be replaced as there is no guarantee that it can hold that torque properly the next time it is tightened.
on the other hand, there are fasteners that are under-spec'd, meaning they can be re-used, and the point at which they become critically fatigued is beyond the expected life-span of the parts they are fastening. the head bolts on a 22re happen to fit into that category.
however, every time a bolt is released from tension, then has tension re-applied, it will loose some of its strengh (and stretch)...
so I'll go back to my previous question: why are you pulling the head after 15k mile?
as mentioned, any fastener when exposed to heat and tension, will tend to 'stretch'. some fasteners are designed to handle this, and others are not. generally speaking, any fastener that has been torqued to spec should be replaced as there is no guarantee that it can hold that torque properly the next time it is tightened.
on the other hand, there are fasteners that are under-spec'd, meaning they can be re-used, and the point at which they become critically fatigued is beyond the expected life-span of the parts they are fastening. the head bolts on a 22re happen to fit into that category.
however, every time a bolt is released from tension, then has tension re-applied, it will loose some of its strengh (and stretch)...
so I'll go back to my previous question: why are you pulling the head after 15k mile?
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#9
The diagram has little black diamonds next to the non-reusable parts. Head bolts for the 22RE do not have this little black diamond next to them, so they ARE reusable.
#10
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Yes and no.
I don't think its totally neccessary, but I feel can't hurt with putting in new bolts and they're cheap.
Napa, Schucks etc all carry headbolts for these motors, something like 35 bucks.
I think it is far more critical to torque and retorque and retorque and then retorque again. then maybe a few more times. Go back in like 500 miles adjust your valves and retorque teh head bolts, guarantee they'll tighten some.
I don't think its totally neccessary, but I feel can't hurt with putting in new bolts and they're cheap.
Napa, Schucks etc all carry headbolts for these motors, something like 35 bucks.
I think it is far more critical to torque and retorque and retorque and then retorque again. then maybe a few more times. Go back in like 500 miles adjust your valves and retorque teh head bolts, guarantee they'll tighten some.
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Yes and no.
I don't think its totally neccessary, but I feel can't hurt with putting in new bolts and they're cheap.
Napa, Schucks etc all carry headbolts for these motors, something like 35 bucks.
I think it is far more critical to torque and retorque and retorque and then retorque again. then maybe a few more times. Go back in like 500 miles adjust your valves and retorque teh head bolts, guarantee they'll tighten some.
I don't think its totally neccessary, but I feel can't hurt with putting in new bolts and they're cheap.
Napa, Schucks etc all carry headbolts for these motors, something like 35 bucks.
I think it is far more critical to torque and retorque and retorque and then retorque again. then maybe a few more times. Go back in like 500 miles adjust your valves and retorque teh head bolts, guarantee they'll tighten some.
#13
These head bolts are not TTY, but have you ever spec'd and mic'd a stock set of head bolts after use? They all vary in length, most aren't straight, and for $40, I'd just get a new set online (unless you are in a crunch). The hot/cold, hot/cold, hot/cold cycles of engines really wear these bolts out. They do a good job for about 20 years, but then its time for new :-)
Check ebay next time, I usually see new sets on there cheap.
Check ebay next time, I usually see new sets on there cheap.
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Replace the head bolts with ARP studs. A little pricey at $149 for the last set I bought. I've installed them in my last two 22RE builds. If I ever do have to replace a head gasket, I won't have to struggle with removing head bolts. I think it's worth it.
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i won't have to struggle to remove my headbolts either,,,i used anti-seize. i reused mine. if they look good, no pits, etc., they are fine. i've reused the same type of headbolts on my datsun inline 6 motors, (same size headbolts), torqued to 80lb, no problems. just torqued my 22RE headbolts to 60lb. even.
"omg, they MUST be replaced, TOYOTA's engineers didn't know crap when they wrote the FSM."
"omg, they MUST be replaced, TOYOTA's engineers didn't know crap when they wrote the FSM."
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#17
"Torque to yield" for anyone who wants to get up to speed.
http://www.freeasestudyguides.com/a1_4.html
http://www.freeasestudyguides.com/a1_4.html
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"Torque to yield" for anyone who wants to get up to speed.
http://www.freeasestudyguides.com/a1_4.html
http://www.freeasestudyguides.com/a1_4.html
#19
I posted it for decoration. Just about every single post I make, you come up with an unintelligent-sounding comment. Now, you're probably not that dumb and you're probably just trying to make an arse of yourself. Lay off, get a life.
If the head bolt is TTY, then the bolt cannot be reused. Not everyone everyone is aware what elastic vs. plastics deformation is, you moron
If the head bolt is TTY, then the bolt cannot be reused. Not everyone everyone is aware what elastic vs. plastics deformation is, you moron
Last edited by Matt16; 11-18-2008 at 10:52 PM.
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and the OP asked if the head bolts could be reused, not if they were torque-to-yield.
why does it seem that you like to flaunt superfluous knowledge as opposed to answering the question?
if you know the bolt is not TTY, then the answer is simple... and if it is TTY, then the answer is likewise simple.
spouting irrelevant verbage as if you're an expert means nothing more than you like to show off.
why does it seem that you like to flaunt superfluous knowledge as opposed to answering the question?
if you know the bolt is not TTY, then the answer is simple... and if it is TTY, then the answer is likewise simple.
spouting irrelevant verbage as if you're an expert means nothing more than you like to show off.
Last edited by abecedarian; 11-18-2008 at 10:51 PM.