YotaTech Forums - 22RE: Re-torque head bolts cold or hot?

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22RE: Re-torque head bolts cold or hot?

It's been about 300 miles since I replaced the head gasket and consensus here is to re-torque the head bolts. Should engine be warm or cold? I used an OEM gasket & new bolts. They were torqued at 58ft/lbs. Should I re-torque to 60ft/lbs, or just the same 58ft/lbs? Thanks

>>>*Other than simple overheat, the #1 cause of head gasket failure is clamping force variations.
Usually when I mention this, the answer is "I torqued it properly!"
*Yes, very likely, but torque, which is a twisting force, means almost nothing when we are talking about clamping force.
Dirt or machinery debris in the bolt holes will throw the clamping force off as much as 50% and more, even though the torque wrench reads perfectly normal.
The same happens when installing new bolts. The very best bolts made will show a rough mating surface at the threads when inspected under a microscope.
When installing new or used fastners, first be sure the bolt will spin in and out ALL THE WAY freely with simple finger pressure. Be sure they are lightly oiled, not too much which can hydraulic lock at the bottom of any blind holes and spoil your day.
Use this simple breakin procedure for any new bolts: Tighten all of them to 50%, back off 1/4 turn, then to 75%, back off 1/4 turn. Then take them to 100%, back off 1/4 turn and repeat. Do a retorque after full warmup.
*This procedure simply assures that the imperfections of the threads seat to the bolt hole threads.
Yes, time consuming, but much faster and less costly than another set of gaskets, the actual clamping force will increase vastly, even though the torque load is exactly the same.
The alternative is you may be additional twisting at the top of the bolt after the threads have come to a stop from excess friction.
If any single one does that, head gasket failure prematurely is gauranteed, plus it weakens the bolt....*EB

I thought these new type Toyota head gaskets don't require a re-torque.

Back in August of 2017, I installed a Toyota head gasket along with new head bolts, and torqued the bolts to 62 ft lb. I did oil the head bolts. Never did do a re-torque. It's still running just fine.

I think the debate on whether to re-torque the head bolts is as old as the stone ages (OK, at least as old as our trucks :wrench:) and I don't think you will ever get a definitive answer. :stir:

22RE Performance says that a re-torque of the head bolts is not necessary when using the Genuine Toyota head gaskets, but they do mention that a re-torque may be necessary with aftermarket head gaskets.

I don't remember seeing a re-torque step in the Factory Repair Manual either.

Then there is the debate on what torque value you should use. The Factory Repair Manual states the final torque should be 58 ft-lbs. Many people in the past have gone with 65 ft-lbs and some have said that Toyota has updated the torque value to 65 ft-lbs, but I have not found any documentation yet that shows that to be true.

:safari:

old87yota is correct on the FSM; there is no recommendation for doing anything after you get the engine started. http://web.archive.org/web/201211101.../7cylinder.pdf

As a result, no one knows what "re-torquing" means anyway. If you're talking about setting your wrench to 80% (46.5 ft-lbs) and sneaking up on that to see what happens, I don't see how that could hurt. But if you "back off 1/2 turn" and then bring the fastener back in, I would expect that to cause a leak. IMO.

Cold.

You are .. Ok I .. am most concerned that nothing's came loose after it has been heat cycled.

Physics says it's going to take more than the initial torque value to move them. I check them at a lower than specified torque reading. If they move at less than the specified torque value it's a sign they have backed out and you maybe replacing the gasket in the near future.

EB's process helps eliminate premature binding and precompresses the gasket so bits like the dire ring are seated more securely.

:good:
i agree... it certainly is a very simple thing to "check" the head bolts...
i certainly wouldn't increase torque values just to check to make sure nothing changed...
I live by "if it's not broke, don't fix fit"

I did use a little oil on the threads if that makes a difference about doing a re-torque?

Don't over think this... just check them and re check the valves while your there... then drive it...

Quote:

Originally Posted by Paul22RE (Post 52420075)

I did use a little oil on the threads if that makes a difference about doing a re-torque?

That's a relative term, yours mine and her little all are gonna vary to some degree.

Fwiw, the arb head stud instructions use an assembly lube not on the threads but on the mating surface since its a friction point.

I wasn't able to dig up the updated torque specs, I do know that there is a TSB that increases the torque spec 4-6 lbs. Google pretty much failed me but it is out there I certainly have it on an archive drive somewhere.

I have had head bolts come loose, regardless of the cause, it's a simple thing to check while you are in there inspecting the valve lash and cam wear which needs done anyway.