Dealer Severely Overtightened Lugnuts!

Messages
214
Location
New York City
I understand your frustration. A similar thing happened to me a few months ago when I went to get my tires rotated. I had to jump on my breaker bar for the lug nuts to finally come off.


But not all hope is lost! I went to a Midas a few days ago to put a patch in my tire. When I went to re-torque my lug nuts, it just took firm pressure on a breaker bar to loosen my lug nuts. So they torqued them pretty close to spec (100ft/lbs)
 
Messages
7,104
Location
Roanoke Virginia
Luckily I do all my own work so I know the torque on them. I’ve had relatives come to my house to get their car fixed and their lugs are on super tight from Sam’s Club doing the tires so that’s part of the reason I have an air impact at home and once they had a flat tire luckily I had brought a breaker bar and pipe because the tire iron it came with wasn’t cutting it at all.
 
Messages
2,288
Location
WA
oilUzzer- we're talking dynamic COF vs. static. As you tighten the bolt, it is rotating (dynamic) the whole time until it reaches the selected torque and the wrench clicks over. The bolt is now at 80ft-lbs. To loosen requires about 20% more as it is now static friction to overcome which is always higher than dynamic (all things staying the same). Imagine moving a large heavy box, initially at rest (static) on the floor. To get it moving requires alot more force, but once it begins to move, alot less to keep it moving. This is static vs. .dynamic . The bolt in your case is at 80 ft/lbs but requires that and an additional 20% or 96ft/lbs to initially loosen

Re: needed torque to remove.

I was doing some research regarding nutbusting torque which had nothing to do with this thread as I am in the market to buy a new impact wrench.

In general, I agree with your static vs. dynamic force ... However, I ran across this Interesting fact posted on realtoolreviews.com:

"When a nut/bolt is hot, it takes LESS TORQUE to remove it than it took to install it! So, if you tighten to 1,000 ft-lbs…..800 ft-lbs can remove it immediately afterwards. The torque is 800 ft-lbs “reverse torque“….not 1,000 ft-lbs “nutbusting torque“. But to the marketing dept, they choose to go with the higher number in order to look better."
 
Last edited:
Messages
1,965
Location
USA
However, I ran across this Interesting fact posted on realtoolreviews.com:

Obviously no reflection on you as you are not the author but that word is used way too loosely on articles.

"When a nut/bolt is hot, it takes LESS TORQUE to remove it than it took to install it!

Again, this is why "links" and information taken from unvetted articles ( regardless of subject matter) need to be taken with a high degree of skepticism and critical thinking plus validation before taking them at their word.

This claim as written ( will address the special case) is totally false on its face. ( granted "hot" itself is a nebulous meaningless term altogether signifying absolutely nothing)

With the understanding that ALL WORKING STRESSES/INFLUENCES ON A PARTICULAR JOINT ARE NULLED AND EXCLUDED FROM THE COMMENTARY....

In properly manufactured fasteners the nut is hardened 2-5 points HIGHER than the bolt ( on the same hardness scale-making it the stronger) so it will pull and hold tension against the bolt thread. (not the other way around).

ASSUMING A PROPERLY TENSIONED JOINT WITH MECHANICAL INTEGRITY- heating the fastener assembly will not negate anything ( tension wise) since thermal growth will normalize and be uniform. If that were not the case then "hot" fasteners would be failing everywhere.

This is a routine test done when engineering joints with a Skidmore.

There is a SPECIAL CASE where a significant amount of heat is "flashed" onto a nut ( either totally or on a facet) which can cause "egg shaped" uneven growth between a nut and bolt which WILL result in a significant reduction in BT. This effect is offset by the fact of physics that given time ( depending on the amount of heat-mass of the fastener dependent)- this joint will normalize as much as possible negating the effect.

Another case can be a class 5 fit where its already so loosey goosy that the slightest delta can result in the special case above- that's also exceptionally rare too.

Note to readers- before accepting claims of these "facts" do yourself a favor and ask what test and conditions and what type of fastener they used to determine their "fact"- you may be surprised.

Where a lot of this comes from in this special case is using mismatched graded components in a joint which have different COF and thermal properties which give the illusion but that's why the qualifier of a "properly tensioned joint with mechanical integrity" is there.
 
Messages
811
Location
sw ohio
Re: needed torque to remove.

I was doing some research regarding nutbusting torque which had nothing to do with this thread as I am in the market to buy a new impact wrench.

In general, I agree with your static vs. dynamic force ... However, I ran across this Interesting fact posted on realtoolreviews.com:

"When a nut/bolt is hot, it takes LESS TORQUE to remove it than it took to install it! So, if you tighten to 1,000 ft-lbs…..800 ft-lbs can remove it immediately afterwards. The torque is 800 ft-lbs “reverse torque“….not 1,000 ft-lbs “nutbusting torque“. But to the marketing dept, they choose to go with the higher number in order to look better."
So let me understand this in the context of the original post- you are going to heat overtightened lug nuts on the side of the road in traffic to undo them? LOL
 
Messages
10,743
Location
MA
So let me understand this in the context of the original post- you are going to heat overtightened lug nuts on the side of the road in traffic to undo them? LOL
Yeah, instead of carrying an impact wrench or a long pipe, you're going to have a bottle of mapp gas so you can heat up the lug nuts when you can't get them off. And of course not do any damage to the wheel cause they're steel stamped wheels and you've taken the hub cap off.
 
Messages
2,288
Location
WA
So let me understand this in the context of the original post- you are going to heat overtightened lug nuts on the side of the road in traffic to undo them? LOL

no I think they were talking about the heat generated when tightening the bolt (friction, etc.) and if you immediately remove it, the "heat" is still present vs. letting it cool off (e.g. removing the lug nut a day later).
They were pointing out that marketing is using this to their advantage.

I was researching nutbusting torque and read that (the heat impact) somewhere else as well ... but that doesn't make it a "fact" as @ABN_CBT_ENGR pointed out.
I just used the term loosely but it was interesting and made me curious.
 
Messages
2,288
Location
WA
So let me understand this in the context of the original post- you are going to heat overtightened lug nuts on the side of the road in traffic to undo them? LOL

Just realized "context of the original post" ...
I wasn't talking about original post. It was stated that it takes about %20 more torque to remove the lug nut (vs. the torque used to tighten) and I don't necessarily disagree but this article pointed out if you remove it immediately (not a very practical thing in real life), it will take less torque to remove and not more ... hence marketing is using this to their advantage. In the above example, 1000 to tighten and 800 to remove (immediately) but they advertise that the tool is capable of 1000 nutbusting but in reality its only doing 800.
 
Messages
811
Location
sw ohio
Just realized "context of the original post" ...
I wasn't talking about original post. It was stated that it takes about %20 more torque to remove the lug nut (vs. the torque used to tighten) and I don't necessarily disagree but this article pointed out if you remove it immediately (not a very practical thing in real life), it will take less torque to remove and not more ... hence marketing is using this to their advantage. In the above example, 1000 to tighten and 800 to remove (immediately) but they advertise that the tool is capable of 1000 nutbusting but in reality its only doing 800.

Thank you- I was not being serious, just yanking your chain, as they say.
 
Messages
1,965
Location
USA
FYI
Interesting video below:

It shows about %20 less torque required to remove. Maybe this also falls under the "hot" category like the 800 vs. 1000 above.

Nut busting torque.
No reflection on you obviously but the only thing "interesting" about that video is that so much false, inaccurate and totally misleading information could be put into such a short span of time. Every single point he made is 100% factually fundamentally and fatally flawed in every detail. It does serve a legitimate purpose as yet another testament as to why "links" ( and the information contained) as well as most "studies' should be taken with a high degree of skepticism and results independently verified by a deep dive into the data and design of experiments the "conclusions" are based on.

Short list-

First, there is a washer there ( see a junkers test)- any "torque" he thinks he had- he really didn't.

Second ( specifically on a lug nut per the subject of the thread)- most lug nuts have the "taper/cone" fit ( like a Morse taper) which adds locking force based on area and wedge effect making a requirement of less tension - that point is not present in his "experiment" ( but then he doesn't claim it- just pointing out his experiment doesn't represent the physics of a lug nut joint so would be inapplicable for any comparison)

Third- "torque" is twisting force. Fasteners pull tension ( physical stretch leading to locking tension)- that's important in context because you don't arbitrarily pick a "torque value" ( based on his thread, nut, washer and slab of steel test rig)

So, if his "selected torque value" did not RISE TO THE REQUIRED THRESHOLD of "tension" required to "STRETCH" the components in the first place- it was a meaningless number. ( which is what I suspect happened)

That's like arguing my "hand tight" is tighter than your "hand tight" when neither one of them are worth anything in the first place relative to required tension of the joint. If those were grade 8, some #200 wouldn't even probably begin to pull tension on the fastener- he most likely just had a mechanical surface contact frictional hold.

Fourth- There was no working load factor in play so without the joint being subjected to stress and normalizing- the test, results and conclusion would be invalid on its face even if done properly in every other area is the design of experiment was understanding "BT" from an in service joint.

Fifth- he clearly doesn't comprehend that "impact" (high F, High A) is a different force than the motor torque and the 2 work together. ( he acts like that number means something relative to fastener tension- he doesn't understand its a meaningless marketing term relative to actual forces imparted on the joint)

FYI, Be careful thinking you are getting actual knowledge from "links".
 
Messages
4,709
So let me understand this in the context of the original post- you are going to heat overtightened lug nuts on the side of the road in traffic to undo them? LOL

I've seen people squirt PB on the lugs.

As to using ohh a torch, maybe a propane torch? Seems stupid, because the whole wheel and tire is hot.
 
Messages
4,709
FYI
Interesting video below:

It shows about %20 less torque required to remove. Maybe this also falls under the "hot" category like the 800 vs. 1000 above.

Nut busting torque.

Leverage. Leverage. Leverage.

Or an impact gun like a W7152.

If these can't help you or they are "frozen on" then you will bend your bar jumping on it trying to get them off. And I weigh 250lbs...
 
Messages
1,965
Location
USA
I've seen people squirt PB on the lugs.

As to using ohh a torch, maybe a propane torch? Seems stupid, because the whole wheel and tire is hot.

Few points on your points

On penetrants - used to have a Lexan model to illustrate this and it could be seen clearly.

Putting them "on" a thread is no guarantee they will get "IN' the thread to do their thing. They advertise solvent, dissolve rust, capillary action down to 1 millionth of an inch and so forth.

That's all basically true and correct EXCEPT ( some thread pitches and fit classes create an exception to this so there are special cases) that a properly dimensioned thread pulled to proper tension is physically touching ( thus sealed under load) and as such has ZERO clearance for the chemical to penetrate into. ( remember, if that were not the case, every threaded joint would leak- if the penetrant can get in- air and other fluids under pressure can work out)

Just remember they don't magically leech in or go by osmosis- if the joint has too much stuff, some thread lockers or is mechanically tight- its not going to get in there without significant rocking and working.

The problem with propane torches in heat shrinking/releasing applications is the available heat and the speed it needs to get there. Basically its cold ( compared to Oxy) so by the time it heats- the other part has started expanding due to transfer and "can" make the joint even tighter until everything eventually normalizes.
 
Messages
4,709
Few points on your points

On penetrants - used to have a Lexan model to illustrate this and it could be seen clearly.

Putting them "on" a thread is no guarantee they will get "IN' the thread to do their thing. They advertise solvent, dissolve rust, capillary action down to 1 millionth of an inch and so forth.

That's all basically true and correct EXCEPT ( some thread pitches and fit classes create an exception to this so there are special cases) that a properly dimensioned thread pulled to proper tension is physically touching ( thus sealed under load) and as such has ZERO clearance for the chemical to penetrate into. ( remember, if that were not the case, every threaded joint would leak- if the penetrant can get in- air and other fluids under pressure can work out)

Just remember they don't magically leech in or go by osmosis- if the joint has too much stuff, some thread lockers or is mechanically tight- its not going to get in there without significant rocking and working.

The problem with propane torches in heat shrinking/releasing applications is the available heat and the speed it needs to get there. Basically its cold ( compared to Oxy) so by the time it heats- the other part has started expanding due to transfer and "can" make the joint even tighter until everything eventually normalizes.

By Oxy, you mean Acetylene?

I also questioned how penetrating lube can work.. when it can't get to the threads .
 
Messages
1,965
Location
USA
By Oxy, you mean Acetylene?
Yeah, just my short text

I also questioned how penetrating lube can work.. when it can't get to the threads .
That was the whole part of the training I used to do- it doesn't

The words used are very carefully chosen and they deliberately don't explain that all important part about that if there is no gap whatsoever ( millionth or not) then its not soaking into anything. They do "penetrate" but only if there is a path to allow it.

Galled, glued and severely contaminated joints don't have any or very much a clear path for wicking)
 
Messages
4,709
Yeah, just my short text


That was the whole part of the training I used to do- it doesn't

The words used are very carefully chosen and they deliberately don't explain that all important part about that if there is no gap whatsoever ( millionth or not) then its not soaking into anything. They do "penetrate" but only if there is a path to allow it.

Galled, glued and severely contaminated joints don't have any or very much a clear path for wicking)

Kind of begs the question.. usually, spraying pene lube on things seems helpful. What situations does it work the best, and how?
 
Messages
1,965
Location
USA
What situations does it work the best, and how?

Depends on the type chemistry of the specific fluid because there are some significant differences between brands ( someone like Mola would be better suited to into those details than me)- I can speak on the testing side because in my years teaching and certifying NIMS, NCCER , Red Seal and others this subject comes up a lot and many vendors have interesting tests and rigs set up to illustrate these things when it comes to fasteners and various chemicals.

In gross general terms- they basically have some form of lubricant/displacement agent, some form of solvent and maybe some additives of various things depending on the brand.

They all work as advertised in terms of lubricating and cleaning ( to the level of the recipe- some lube more than clean, others clean more etc.)

Problem is, they have to physically get in there to work and that's the problem. They all must have a gap and that gap must allow the fluid to enter while any trapped air or other substance can get out. ( that's 2 different scenarios because if sludge is in there- the thinner lube has a hard time displacing it unless it can literally inject or percolate)

Start with the fit class ( see Machinery's Handbook)- basic threads are around 75% ( leaving a 25% gap)- it takes a good bit to clog them up so that's where it works best. The lower the class- the lesser the gap ( and the easier to clog it)

Then theres the run ( length/count of threads engaged)- if theres a mechanical defect, do the best you can because no unicorn oil will negate that. Over the run- the fluid has to meander and work down to the base.

The insurmountable issue comes when either the crud is so packed/condensed that its hard as cement or you have damaged/closed geometry creating a seal like a valve plate.

As said, if the chemical cant get in there- it cant do anything. If it can get in there- they will all make a significant difference.

At the end of the day, a human has to evaluate the joint scenario and pick the best course of action based on the specifics of that individual case.

Flash heating and cooling can break/crack stuff creating a path and a thermal capillary action like solder, mechanical tapping can ( not to the level of damaging thread or other components), mechanical working back and forth can too. ( or any combination)
 
Top