Slightly stripped head bolts, should I replace?

[WHITCHY]

I just had a look at my head bolts on my 4age before I put them back in and on all of them the first 2 rings of thread are stripped and flat, is this normal/ok to re-use or should I go and get a new set of head bolts? or can they be repaired?
Thanks for any help!
Cheers.
-Whitchy-

[kingmick]

they are one use bolts! threads need to be chased in the block!

[WHITCHY]

every where else I have read the 4age bolts are "torque to yield" so they can be reused?
Cheers.
-Whitchy-

[Lachie]

Torque to yeild? The yeild strenght is the point where the bolts will start deforming plastically i.e. they''l deform and they won't change back to their original shape. Whats the cost of a new set of head bolts? I'd use new ones if I were you, like kingmick says - one use bolts!

[JustCallMeOrlando]

Just get yourself some new ones. My 1G ones looked perfect, but there was no way I was going to reuse them. I replaced all of mine for $92, straight from Toyota, and i'd imagine you don't have as many, nor should they be as expensive because they'd be more common.

[o_man_ra23]

they are one use bolts! threads need to be chased in the block!

nuff sed

TEN!!

[river]

Hi,

As the above posts - replace them. They are one-use bolts and the money you think you'll save in re-using them could become quite costly, especially on a head bolt.

Don't even think about getting them rethreaded for re-use, as they've passed their usefulness already. Get some new ones.

seeyuzz
river

[Shifty]

Just get yourself some new ones. My 1G ones looked perfect, but there was no way I was going to reuse them. I replaced all of mine for $92, straight from Toyota, and i'd imagine you don't have as many, nor should they be as expensive because they'd be more common.

I would be surprised if they weren't the same as 1G items.

Regardless, they should be replaced for sure.

[WHITCHY]

Ok, thanks for the info, I just ran and got some from toyota for $80!
Cheers.
-Whitchy-

[JustCallMeOrlando]

The 1G model number doesn't correspond to any other Toyota number. How many is there Whitchy, how much were they each? I got prices as much as $9 each and ended up paying $6.x

[WHITCHY]

there are 5 intake and 5 exhaust so 10 in total, and I got them for 6.30 each. So a total of 63.80! not $80!sorry!
Cheers.
-Whitchy-

[allencr]

for a Toyota 4AG, They are NOT torque-to-yield, and they are NOT one use bolts. Hasen't this been gone over & beaten to death?

Torque-to-yield bolts are one use bolts, but the Toyota FSM says nothing even close to that about its head bolts, though on the later models/editions there is a bolt torquing method, usually called 'torque angle'. Why does almost every squirrel seems to think that also means the bolts are one time/torque-to yield????????????


I am, and you should also be, very concerned about "all of them the first 2 rings of thread are stripped and flat"!!!!!
I don't know exactly what you mean, but whatever caused it will happen again, and any deformed threads mean that any tightening method, except measuring streatch, will be incorrect.
CHECK the block & figure out what happened to them, first thing!

[love ke70]

allen, what about 1G bolts, they torque to yeild or reuseable?

i remember reading, that often the thread is flattened a bit and people get a bit worried about this. but its meant to be like that because it gives a more solid thread grip.
rather than having a narrow ridge, its flattened off a bit.

maybe check them in the block before you put the head back on and see how they run?

[Jorrs]

^ yeh id prob go with that, c how they run and then decide, though wats the cost of new ones ?

[kingmick]

for a Toyota 4AG, They are NOT torque-to-yield, and they are NOT one use bolts. Hasen't this been gone over & beaten to death?

Torque-to-yield bolts are one use bolts, but the Toyota FSM says nothing even close to that about its head bolts, though on the later models/editions there is a bolt torquing method, usually called 'torque angle'. Why does almost every squirrel seems to think that also means the bolts are one time/torque-to yield????????????


I am, and you should also be, very concerned about "all of them the first 2 rings of thread are stripped and flat"!!!!!
I don't know exactly what you mean, but whatever caused it will happen again, and any deformed threads mean that any tightening method, except measuring streatch, will be incorrect.
CHECK the block & figure out what happened to them, first thing!

my advice still the same, thats why i have a box of head bolts in the shed that have only ever been used once! not worth lunching your engine of $80, especial as most people on here expect way more than stock out of the engine! $80 or a chance all the time and money you put into your engine can be wasted, even more so if the bloke before over torqued them.