retorque stock head bolt after 20 000miles

[sylquebec]

HI! I just bought a rebuilt 7mgte with 20 000miles on it. I was looking at the mechanic shop sheet detail and saw that they torque the head at the 58lbs torque spec. My question is...can i change the bolt for ARP ones? Or should i re torque the stock ones only? And what will be the exact procedure? Loose them one at a time and re torquing the bolts at 72 lbs or should going in 3-4 step as 20-40-60-72? Is it important as the head gasket was already compress?
Thx for the reply. I dont want a BHG

 

[87M-GTE]

I dont think you have to de-torque before you re-torque. The max the stock head bolts will safely do is about 75ft/lbs. Use the TSRM torque pattern, and torque at a constant interval, from 58 to 60 to 65 to 70 to whatever you decide to go to.

 

[WhtMa71]

You're supposed to crack them loose and then retorque to 72 one at a time in sequence. Don't take all the torque off of them or you might risk messing up the head gasket. It wouldn't be a bad idea to go steps but I don't think its necessary.

 

[Keros]

Yeah, you can change the bolts to the ARP studs.

A few cautions though. Remove each stock bolt one at a time in the sequence of the TSRM and replace it with the ARP stud, but torque each new stud to the same torque as all the bolts were that you started with. Once you have all the ARP's in, then retorque them as required in the TSRM sequence.

It's not the best solution, but it's arguably better than having retorqued stock bolts.

 

[Jaguar_5]

I dont think you have to de-torque before you re-torque. The max the stock head bolts will safely do is about 75ft/lbs. Use the TSRM torque pattern, and torque at a constant interval, from 58 to 60 to 65 to 70 to whatever you decide to go to.

Wrong!
Btw. jumping from 58 to 60? Have you used a torque wrench before? They can't make such small increments when tightening the same fastener. You will effectively be measuring the mechanical resistance, not the torque!

You're supposed to crack them loose and then retorque to 72 one at a time in sequence. Don't take all the torque off of them or you might risk messing up the head gasket. It wouldn't be a bad idea to go steps but I don't think its necessary.

I think what you are trying to say is correct, but the way you're wording it is very unclear. If you are talking about the correct way, the increments are completely unnecessary, you're more likely to get a false reading imo. The point of doing increments is for even torque across the entire head, in this case the rest of the fasteners are already loaded.

Yeah, you can change the bolts to the ARP studs.

A few cautions though. Remove each stock bolt one at a time in the sequence of the TSRM and replace it with the ARP stud, but torque each new stud to the same torque as all the bolts were that you started with. Once you have all the ARP's in, then retorque them as required in the TSRM sequence.

It's not the best solution, but it's arguably better than having retorqued stock bolts.

And another wrong answer!
[edit]Re-reading this, I believe you're actually correct! The problem with explaining this procedure, is if you're not extremely specific, there's some interpretation that maybe someone will thing to loosen the bolts one at a time, but loosen all of them before installing new fasteners[/edit]

Do not loosen all the bolts at once!

Refer to the TSRM sequence, start with the first bolt, crack it loose, torque it down - IIRC 72 ft/lbs is safe for the stock bolts, but they will not be re-usable

After one is torqued down, move to the next, this allows for maintaining the most consistant torque across the gasket, to keep it sealed.

You can use this same method to switch to arps, by taking out the bolts one at a time BUT you are more at risk of losing the seal of the gasket.

 

[jdub]

Not a big fan of removing stock head bolts and replacing with ARP hardware and not replace the HG as well. Too easy to induce a failure. I'd "crack" each head bolt back (1/8th CCW turn) and torque straight to 70 ft/lbs...using the TSRM pattern, of course. Don't use your torque wrench to crack the bolts.

Keep in mind it already might be too late for a re-torque...20,000 miles is a lot. If the HG already has a small leak, this can make it worse. Basically it's a 50/50 whether it will do any good or not.

 

[Poodles]

You CAN NOT install ARP studs that way. The stock bolts only use half of the threads in the block, the studs have to go all the way in and on the two blocks I have they WON'T unless you run a tap down them to clean em out.

Wasn't the new torque supposed to be 76ft/lbs? (only reason I remember is that it's the same as the lug nuts)

 

[IJ.]

ARP Studs into a block that hasn't had the threads chased = cracked block.

 

[Jaguar_5]

Aah yes, that small detail, forgot about that It's been a little while since I put my head on!

 

[IJ.]

Don't like installing studs back into an oily hole, I'm guessing Toyota left the stock bolts so short to prevent them hydraulicing in the block and giving a false reading if there's Oil in the holes.

 

[sylquebec]

Thx for the fast reply guys. So i will Re torque my stock head bolt to 72lbs one at a time after cracking the bolt following the tsrm procedure. I understand the 50/50 good or not, but for me, there is no difference between BHG now or later...

THx everyone!

 

[CATarga]

IIRC, and correct me if I am wrong, but aren't the head bolts torque to yield head bolts, and are designed to stretch as you torque them. Wont cracking them back even a little reduce the stretch and make getting new correct torque specs impossible, the same as when removing them. Wouldn't it be better to just torque them in order from 58 to 72 in one or two passes?

 

[Poodles]

No, they aren't torque to yeild. Torque to yeild bolts cannot be reused.

 

[queenskid926]

ok im in the almost the same situation as the original poster, so when it comes to retorquing is it better to crack it halfway loose 1/8th of a turn and then to 70 or just torque them straight to 70 without cracking it loose?

 

[WhtMa71]

Crack them loose first.

 

[Muzy]

My way of thinking would be, new head bolts and a new gasket now. A little more work
but at least all your fluids are not contaminated. Making the job easier. muzy

 

[phillyd]

My way of thinking would be, new head bolts and a new gasket now. A little more work
but at least all your fluids are not contaminated. Making the job easier. muzy

I am in the 'wanting to re-TQ my HG bolts boat' too...I would like to replace my HG, but don't want to deal with having to get the block and or head resurfaced.

Should I just re-TQ the bolts, leaving the HG alone and hope all works out well...or...should I replace the HG, get new HG bolts/studs and not mess with any block and or head resurfacing?

Are the ARP bolts or studs a better choice? IIRC more people use the studs...is this personal preference or best practice?

 

[Muzy]

I am in the 'wanting to re-TQ my HG bolts boat' too...I would like to replace my HG, but don't want to deal with having to get the block and or head resurfaced.

Should I just re-TQ the bolts, leaving the HG alone and hope all works out well...or...should I replace the HG, get new HG bolts/studs and not mess with any block and or head resurfacing?

Are the ARP bolts or studs a better choice? IIRC more people use the studs...is this personal preference or best practice?

Phillyd I am no authority on this, but from what I can glean from reading
many post's such as this. Is if you are not exceeding 12 or 15 psi (just going
from memory) a quality head gasket will be good. As long as you increase
the torque # up from factory spec. to 70 or 75. This the reason for going
arp fasteners, be it bolts or studs. As the factory fasteners are good' the arp
are better, as indicated in above replies.
As for as resurfacing goes you will not know until disassembly. Clean both
surfaces up than measure with a strait edge. (I'm sure somebody will chime
in with what those values would be)
There are alot of good threads on this already. Even a sticky I think. So read
re read until you are confident. Once disassembly is done you will have better
idea how much more work will be involved. If you decide to retoque, its a crap shoot. Feeling lucky let em roll. muzy :icon_bigg

 

[Poodles]

IF and ONLY IF the headgasket is not currently leaking will a retorque on the factory headgasket seal.

When the factory (or factory style)headgasket leaks, the metal sealing rings are displaced from where they need to be to seal and no amount of torque is going to seal them.

Studs load the block better as they use all of the threads in the block and don't put wear on them...