Double Nut Method to Tighten Head Studs

(Lou) #1

List: This may sound trivial but ,I used the double metholdof installing one of the head studs. I was wondering is there is a right way to use the double nuts.

One: screw the first nut until it reaches the end of the threaded area and then screw the second nut until it stops against the first nut.


Two: screw the first nut 2/3 of the way down the threaded area and then screw the second nut hand tight against the first. Then, using two wrenches, tighten the two nuts against one another: one wrench turning clockwise and the other, counterclockwise

I am using stainless steel nuts

The Devil is in the details.
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(Paul Wigton) #2

Either method is workable.

(Rob Reilly) #3

There is no need to run the first nut all the way down the threads. Just go enough so you get full thread engagement on both nuts, then tighten them against each other. To install, turn only the second nut. Snug, no need for high torque. Clean threads make it easier to remove the nuts afterwards.

(Lou) #4

Was Double Nut Method, Now Head Stud Installation.

OK, so I will use the Double Nut method with the nuts in the center of the threads.

So let’s move to the next step. As I related previously, I drained the coolant out of the block and blew the block thread out with compressed air. Despite that, when I lower a stick down into what I think is the threaded area of the block and withdraw it, there is about 1” of viscous yellow material on the stick. I assume this was too viscous to have drained out via gravity, or maybe it’s actually inside the threaded area that forms a small cup for the stud bottom.

I can think of one or two ways to deal with this. I could knock out the freeze plugs and wipe the threaded area clean, or stick something down the block holes (A giant Q-Tip) to absorb the moisture. I could also use a hack saw to make a vertical cut in the head stud threads so any moisture could squeeze out of the female threaded area (someone already suggested this). Or use compressed air at a low pressure move the moisture out of the female threads. .

Any opinions?



(Rob Reilly) #5

Long Q-tips. Search for cleaning swabs, cotton with a 6" wood handle. You will need a whole package. At Fermilab the vacuum techs use them by the crate for cleaning threaded holes.

(Pete55Tbird) #6

Lou, When I was in the Air Force, the saying was: We measure with a micrometer, we mark it with a
piece of chalk, then we cut it with an Ax. In other words; whatever works. Pete

(RustfreeMike) #7

Hi Lou - one thing I’ve done to clean those holes is to get a piece of metal or stiff plastic tubing long enough to reach and narrow enough to fit in the threaded hole. Duct tape the end of a wet vac hose, sealing it off. cut a small ‘X’ in the tape with legs approximately the same size as the diameter of the tube. Pop it over the tube. You’re basically making a very narrow vacuum attachment. Suck out offending gunk and liquid.


(Frank Andersen) #8

It’s important not only to get moisture out, Lou - you have to ensure that there is no solid residue left either…

Mangling the studs with a hacksaw will not eliminate solid residue - and removing the freeze plugs, while efficacious, seems a bit overkill at this stage. Compressed air, and some bottom scraping should be enough…

However, the real proof of the pudding is that the relevant studs protrude equally when inserted - fairly easily checked. And it’s unlikely that none of the studs are seated…

As for double nutting; there is no point in tightening the studs beyond seating. As you torque up the head nuts, everything moves in the clockwise direction…

xj6 85 Sov Europe (UK/NZ)

(Lou) #9

In think a combination of the suggestions will do the trick to clean the female stud end.

I can suck the goop out with Mikel’s suggested small vacuum hose and then wipe it Rob’s Q-Tip recommendation.

Thank you gentlemen


(Jochen Glöckner) #10

That’s funny, Pete - same idiom in German! And I wasn’t even in the Air Force …


75 XJ6L 4.2 auto (UK spec)

(Erica Moss) #11

I do the second. The only reason is that if you make it tight against the end of the threading, and it slips just a bit as it often does as you are snugging the two together or tightening the stud in place, then when you remove the outer nut, the first one on can be bound against the end of the threading which then requires you to grasp the stud with pliers or something so you can get that nut off without loosening the stud again.

(Frank Andersen) #12

Gripping the stud with anything is a no-no, Erica - any denting marks on a stud will weaken it…

xj6 85 Sov Europe (UK/NZ)

(Erica Moss) #13

Right which is why I prefer not to let them get stuck in the first place by running the nuts to the bottom of the threads.

(Lou) #14


I think the majority felt that putting the two nuts together in the middle of the thread was somewhat preferable to running them down to the bottom of the thread.

Done that way, one can grasp each nut with a wrench and tighten against one another and loosen, for removal, when done, without affecting the final location of the stud.

I think you could also use the same process for nuts driven to the end of the thread.


(Carl Hutchins, Jr. ) #15

Tis interesting, for sure. Idioms are adopted and spread.

When I served in your beautiful country, we adopted one. Macht Nicht. We bodged it to Mox Nix!!

Very expressive and often used!!!


(Carl Hutchins, Jr. ) #16

I forgot!!

Why not a proper stud tool. I’ve one or two. One better than the other.


(Frank Andersen) #17

While we are discussing double nut tightening the studs, Lou - which is not necessary; the double nut method was ‘invented’ to extract stubborn studs…:slight_smile:

xj6 Sov Europe (UK/NZ)

(Lou) #18


I have to admit that the double nut method is far superior to most, if not all methods of driving a stud, and probably other related parts of that nature, both auto and non-auto.

In fact, I am coming to the conclusion that the problems I had with the car, the head studs coming loose, is a result of not driving the studs sufficiently into the block. I have no way of measuring, but I believe the double nut method creates more torque than other methods of driving the studs home. And, with no damage to the stud.


(Jochen Glöckner) #19

Wow, Carl, this is the ultimate German idiom for every occasion from “doesn’t matter”, “don’t worry”, “that’ll do” to “better not talk about it any more”:slight_smile: And the way you pronounce it would be rather Bavarian than Northern German accent.


75 XJ6L 4.2 auto (UK spec)

(Robert Wilkinson) #20

Kann sein, Jochen. I thought it was “Warum ist die banane krumm?” :slight_smile: