Wheel Nut Torque

I have 2 pneumatic 1/2 drive impact wrenches and they both have knobs for turning down the wick.

I also have a 3/8 drive air ratchet wrench and I have seen a lot of others around, but never seen one with any control on it

It might be worth noting that the torque ratings of some of these pneumatic impact wrenches have been significantly increased over the years, to the point where some of the older 3/4 inch drive tools have been rendered almost pointless coz the newer 1/2 drive tools deliver the goods.

In a drawer in the garage somewhere I have a Snap-On catalogue dating back to 1978 which has some figures to illustrate the point

I've never heard 'wrench' applied to anything other than a spanner... Or in a medical context.

Do be aware that the inherent flexibility of extensions and adapters lowers the peak torque available...

For maximum efficiency the socket needs a good connection to the tool. Any "slop" and you could lose a lot of transfer of torque. One reason to use good quality impact sockets without any extensions or adapters.

I was watching a video, of two guys replacing a front cradle on a Honda.

And part of the video, involves the removal of bolts holding various bits of the suspension.

The presenter, who was doing most of the videoing between steps, said he was using "mechanics butter", without mentioning a brand name or product number. That's all I know about it.

But not many things will directly attack rust.

Solvent can only work, if capillary action allows the solvent to advance into the affected area. If the path is blocked with rust, that won't work.

Whereas a mixture of a bit of phosphoric acid and other things, at least there is a known chemical reaction between the rust and the material being used.

The term "butter" implies a gel, a gel which doesn't fall off when you apply it. Straight phosphoric acid, one of its problems is it runs right off. And then you'd have to build a containment to hold the liquid. And some of the spots needing the treatment, just aren't going to work.

I found one material, which is 99% petroleum (unidentified weight) and while the MSDS does not mention phosphoric acid, a sentence further on warns of "phosphoric acid vapours on combustion" as the stuff is flammable. Yet the people who have tried the material, half said flat out "it doesn't work", and the other half could be stooges.

Google is not very good at finding things today, and the old problem of searches being less deep at one time of the day than another, that's just magnified by the AI doing the search. Later items on say, page 4, are totally and utterly unrelated to the topic of the search.

In another group, a person was complaining they could find nothing at all on a certain topic (which really should be detectable), so I don't know if duckduckgo would be better for this or not.

Well, duckduckgo really works. I FOUND my video.

An actual sciency test. Handy.

There's no phosphoric acid in the winner there. Apparently the best automatic transmission fluid for this, is a "synthetic".

I found my Mechanics Butter video, using duckduckgo. I hope you enjoy this vid as much as I do. It gets in their way. Saw if orff.

# How To Replace a Rusted Subframe On a Honda Accord # 2:00 minutes 5:28 minutes

Now I can go back to my vid of my two heroes and their saw.

Paul

And another reason for using a proper impact socket is that you dont wind up in A&E when the thing shatters

Hmm…

Americans tend to use wrench rather than spanner

Torque wrench is a specific tool. Why we don’t use the term Torque spanner I have no idea.

Impact driver is a specific tool, the older ones were ( in simple terms) ‘tough’ screw drivers you could hit with a hammer or were air driven and had a hammer action.

There was also the air wrench - over used in tyre fitters all too often - which was air driven.

I suspect the modern battery ones have mixed the terms a bit.

I assume the drivers, which have a smaller ‘tool holder ‘, the ones I’ve seen look like the common 6mm hex size, have a hammer function.

My wrench has 1/2 “ drive but no hammer function.

But that only works, if the item is prepared to "give". If it is really held fast, it just takes the stud past failure. There's no problem, with power tools, with busting stuff right off. Tapping, hammering, or vibration, might be more useful, because they're not necessarily taking the metal into the same regime. That's concentrating on shaking the rust loose.

And one other reference I could find to "using a torch", the individual indicated they used a squirt of "freeze mist", which used to be a freon in a spray can. That stopped being sold because of the ozone layer, but it could achieve a pretty low temperature. And that's how that person would get a larger delta_T between stud and nut.

What you want though, is a method that is reproducible from situation to situation, rather than "works about half the time". And it also works in your favour, by not busting stuff (reduced peak torque needed).

The winner of the ghetto methods at the moment, seems to be a 50:50 mix of ATF and acetone. Not that I would be looking forward to using that. Apparently it does not work that quickly, so you can't be in a rush.

A little secret, the ATF is providing two things: some lubrication and phosphorus. It's the phosphorus that attacks the rust scale.

ironman is correct; the acetone or MEK thins out the ATF and allows the phosphorus to wick into the rust scale."

There are a few things on cars, that really do need exceptional torque. It's just my personal observation, in snapping a couple studs off, that you want to think a bit more about what you're doing before going all cowboy on it. If you use a breaker bar, that helps limit how much torque gets applied -- unless you jump on the bar in a rage, which busts the stud off.

There's nothing wrong with power tools. They speed up a process, if you have a lot of fasteners to remove. Depending on how much torque they generate, they can also give you a lashing, if something doesn't really want to give. As you get older, your joints and bones just aren't the same as when you were 18 years old and "bulletproof".

Paul

Would phosphoric acid actually work for a rust seized bolt? If phosphoric acid actually penetrated into the threads it doesn't remove anything, it just converts the rust into a hard iron phosphate which is still in the threaded hole.

Much better to try and use something penetrating and lubricating - but perhaps having to leave the lubrication days to penetrate.

A home brew of automatic transmission fluid and diesel is often recommended for difficult seized components but I'm sure something similar does come in a spray can.

A similar bit of history, back in the early 1970s I rescued a 1952 Triumph Mayflower in Rainham, Kent, from being scrapped. The owner had a car with a wrecked engine. He had got it home somehow (I didn't find out how) and it was parked in his front garden. He had taken it apart and found out what was wrong (pistons seized in their bores but he couldn't find a source of parts to do anything with it, so it stayed as a dismantled non-runner in his garden for years. Eventually his wife told him to get rid of it. By coincidence, his neighbour worked in the same team as me and he told me about it. I called on his neighbour who told me that if I could get it running and drive it away I was welcome to it.

I had a friend in London who was a professional mechanic, and he told me of a company in Greenwich (South east London) that he used for parts for old cars. I got in touch with them and they confirmed that they could source Mayflower parts, so I took up the challenge and over 5 weekends I managed to get all the bits I needed to get it running, and was ready to drive it away. The ancient battery had sat by the doorstep in all weathers, and it took a fortnight on a trickle charger for 24 hours a day to get enough power in it to start the engine, but I had a running car. I paid for it with a 4p stamp to the owner to send off the log book for change of owner. I discovered that it was legal to drive a car with no MOT to a garage for a pre-booked MOT, and it failed on rusted brake pipes. The garage said that it was going to be a problem because they hadn't managed to undo the old ones, so it was going to take some time. So I left the car there and told them to take as long as they needed. They tasked the apprentice to squirt PlusGas on all the brake line fittings every evening before leaving work, and then first thing each morning to try a spanner on all of them and if any of the connections moved, they had to inform the mechanic. That regime finally got all the old brake pipes off and they were replaced after 11 days. So PlusGas did work, but it wasn't a quick fix.

As a corollary, that Mayflower lasted me another 4 years before the rust got too bad to repair for an MOT. During that 4 years I used it as a daily driver to commute to work and it took me and a couple of friends and a tent on a summer holiday which was a 2,300 mile tour of Scotland and Wales, completely trouble free. I still have a photo of that car parked under the sign at John O'Groates. I am the taller one in the picture.

Well, the other thread I found, relates a story about how much torque was required to remove a rusted item and they compared a number of solutions, and the ATF-acetone had the lowest torque required. But a comment I could find elsewhere claimed it took a while for the stuff to work. And you would think the acetone would have long since flashed off by then. The acetone is supposed to enhance wetting on the way in. When it (somehow) evaporates, pulling in the ATF behind it.

The only thing that concerns me about this recipe, is whether all ATF contains phosphate or not. One individual claimed the best ATF was "synthetic ATF" (presumably synthetic base oil).

And the article here, makes it clear that ATF is a "soup". This does not inspire confidence.

It's possible ATF by itself, would start to work on the outside of the item. The trick is to find the best partner to go with it. If the ATF did not act upon surface rust, you would be suspicious that the composition had changed.

You would think for stuff in spray cans, there would be better head-to-head comparisons on the web.

I've never found WD-40 to be good for anything, in terms of freeing up something, so we can take that one off the list :-)

Paul

However rust is much bigger in volume than the iron or steel that its made from

Iron phosphate shrinks it.

Also never forget heat. Induction coils that heat a stud red hot, or welding a nut to it, shifts breaks the 'seal' on the seizure.

Mechanics will use everything until something works.

More importantly; if you are undoing a tight nut/bolt you can afford to use a high impulse energy because at worst after an excessive input of energy the nut spins a turn or so when released. But driving screws they get tighter as they go in and excessive energy will snap them and/or drive them in too far. So for an impulse wrench you need at most two or three high impulse settings; for a driver you generally need much smaller impulse energy *and* a fine adjustment for different sizes and materials being screwed into. Having used a fairly small impact wrench for driving screws it requires extreme care to do it accurately without over driving, while a proper impact driver just needs the right setting.

The impulse drivers don't actually have a hammer function. That is confined to drill drivers which use it for masonry drills, not screws; and don't have an impulse driver function. Impulse drivers just have a rotational impact function, and are not really usable for drills. So they are separate tools.

The method I have often used in the past, to free up rusted nuts and bolts, is...

Heat up the nut, then spray with penetrating oil, to cool it, particularly at the interface between the two threads, and cooled down to the point where the oil is not vaporised. In the cooling process, the oil will be sucked, or drawn, in along the thread, between nut and bolt.

Induction coil heating or welding followed immediately by quenching with Artic Spray is virtually guaranteed to work.

Quite. And I don't think I'll need to worry about losing torque through sloppy adaptors as I've ordered a *beast* of a wrench: DeWalt DCF900. Over 1300ft-lb of nutbusting force! And not one of those fake ones that are all over Ebay. The real deal....

I have a couple of Bosch drivers which can do both in the one tool.

Yes, it does - and I would be very wary of using full power on anything rusted-up without soaking it in penetrating solution for several days prior. I just thought it would be handy for problematic things like crankshaft pulley bolts and such like. Not that I've had to tackle one of those for over 40 years, but you never know...

It's clever the physics of these things. I'd have thought they'd have twisted your wrist right off, but you hardly notice it!