Peugeot Boxer wheelnut torque

Sep 24, 2013
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I've just been over all my wheel nuts (bolts) to check that I can undo them after having four new tyres fitted. It took me standing on a 2ft breaker bar to shift most of them. I re-torqued up to 160Nm (Peugeot recommended?). What is the thinking on putting copper-slip on the bolt shoulders (not the thread). The bolts came free with a load crack when I finally managed to loosen them. Standard steel wheels.
 

pappajohn

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thats the problem with tyre fitters.......they dont know how to use a torque wrench and the windy guns just aren't accurate.....even if they know how to adjust one.

i wouldnt put any lube on the bolts....even on the shoulder.
 
Sep 23, 2007
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Here something I wrote sometime ago for a customer. It explains about dry and lubricated threads and torque. Re reading it now, not sure even I understand it.



According to the Nylok website, the applicable torques for Nylok locking nuts are defined as:
Installation Torque – The highest value of prevailing torque produced the first time the self-locking fastener is being installed. This is taken during the first five revolutions after engaging the locking element and before seating.
Seating Torque [Loading Torque, Tightening Torque] – A value of torque typically measured in “inch pounds” applied to a fastener to induce a compressive load under the head bearing surface that results in creating an axial load (pre-load).
Prevailing Torque [Running Torque] - An average measure of frictional resistance produced during rotation in either the installation or removal cycle. It is independent of clamp load. This is unique to self-locking fasteners and components.


Also on the Nylok website, it references a torque reusability spec for internally threaded fastener from a National Aerospace Standard (NASM25027) for max locking torque for installation of 150 in-lbs for ½-13 nuts. However, the IFI (Industrial Fastener Institute) Standard 155 (for internally threaded fasteners with a locking element) lists a prevailing max torque of 154 in-lbs. So this makes me believe that the NASM value is for the prevailing torque, not the installation or seating torque. This value is size dependent, so each fastener size will have a different prevailing torque.

If we interpret that information to mean that it takes approximately 150 in-lbs just to rotate a ½-13 Nylok nut without any additional torqueing taking place, then I believe that we can add that to the “standard” torques of 517 (dry) and 444 (lubricated).This gives a torque of 667 in-lbs (55.6 ft-lbs) for dry fasteners and 594 in-lbs (49.5 ft-lbs) for lubricated fasteners when used in combination with a Nylok nut.
An important note that I found while doing my research is that the clamping face of the rotating portion (nut or bolt depending on the installation) should also be lubricated to eliminate the frictional effect of that face from the effective torque applied. While this seems logical, it is not something that we typically do or recommend. According to one source, approximately 40-50% of the torque applied is used in the face of the nut.
Here is a table of values that I compiled that is a little easier to reference than reading through all of the text. For future reference, I used all of the respective data for each of the thread sizes that we commonly use.
clip_image002.gif

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Aug 6, 2013
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I have greased the wheel nuts or bolts on every vehicle I've owned without issue. Grease-free they are difficult if not impossible to release and when they're being tightened there is a danger of surface or thread damage from picking-up or micro-welding. I really don't care what the manufacturer says - especially as every nut / bolt on the vehicle underside that is subject to corrosion is assembled dry causing difficulty and expense during repairs. Paranoia about wheel nuts / bolts coming loose can be addressed by drilling & wiring or strange plastic pointers - at least that way the wheels can be removed at the roadside.
 

Techno

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Greasing allows over tensioning the thread and will come undone easier too
I've never had and issue with cracking a thread it just requires a longer bar.

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dave newell

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Many people have had no problem with greasy nuts but a few have had them come undone, not funny when a wheel parts company with the vehicle at 60MPH! Wheel fixings should be torqued up to the correct figure with clean dry threads, That's all folks!

D.

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Badknee

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Full timing for five years and loving it!
When I was on tippers we were always getting punctures, wheel brace and six foot scaffold tube, jump on them till they cracked and they were tight enough. :D
 
Aug 6, 2013
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Wheel fixing torque is determined for dry clean bolt threads and contact surfaces, they should NOT be greased as that can lead to inaccurate torque setting.

D.
It can also lead to them being impossible to remove. I understand the theory and that what you say is correct but I would ask why is the torque setting quoted for dry fasteners? It could as easily be stated for clean & lightly lubricated fasteners thus assisting removal. I have lubricated wheel nuts / bolts on every vehicle I have ever owned. I don't use a torque wrench preferring 'feel' and common sense. I have never had a nut or bolt come loose nor have I ever damaged a steel or alloy wheel. To my mind if wheels becoming loose is a major issue the fasteners would be, or should be, provided with a locking device.
 

Charlie

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I simply cannot understand how folk can argue with the opinion of a respected expert !
Whilst is possible to lube wheel nuts or bolts and get away with it it is not the thing to do ....

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Aug 6, 2013
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I simply cannot understand how folk can argue with the opinion of a respected expert !
Whilst is possible to lube wheel nuts or bolts and get away with it it is not the thing to do ....
Sometimes safety recommendations are belt & braces. Just to encourage my potential demise I've never used a torque wrench on wheelnuts either. I'm very aware of how and why wheelnuts can come undone and I'm careful about how they're tightened but I don't believe they should be impossible to release using the tool supplied by the vehicle manufacturer. Nor do I believe I should have to carry a torque wrench (my 3 live in my workshop). I may not be a respected expert (and definitely no disrespect to Dave Newell intended) but I've been doing this stuff since I was 13 years old and nothing has fallen off or failed due to my workmanship on any two- or three- or four-wheeled vehicle I've owned since then.
 

Charlie

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Tony I understand what you are saying ..

But perhaps you've been lucky ? Frankly to encourage anyone to do something that not only decent technicians advise against is well ..... Well lets just say I wouldn't do it.

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dave newell

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I once did a teacher training course and part of the assessment was a practical lesson given by each of us, I did mine on how to remove and replace spark plugs. I took an old cylinder head in with the relevant tools and delivered my lesson which included getting several of my classmates to "do the practical". I was marked down 10% because none of the ladies could undo the spark plugs, the course instructor/administrator said they were obviously too tight. I said try driving your car home with loose spark plugs but make sure you have the AA number to hand! (think that remark cost me another 5% though).

Just to clarify (or further muddy the water) a point about lubing wheel bolts/nuts, some vehicles are specified to have "light greasing" on cone washers but not on threads. As for being able to undo wheel nuts with the tools supplied I'd like to see anyone do that on my Iveco which comes with a 2 foot long wheel brace but the nut torque is specified at 340NM DRY! The point being to tighten them to the correct torque and lubed or not as dictated by the manufacturers.

D.
 
Aug 6, 2013
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Tony I understand what you are saying ..

But perhaps you've been lucky ? Frankly to encourage anyone to do something that not only decent technicians advise against is well ..... Well lets just say I wouldn't do it.
I wouldn't encourage anyone to do it my way - I was offering an opinion on what has worked for me. Luck? I wish I had that much luck in other areas :). I did once own a fairly tidy Morris Minor with nice clean painted wheels. When one fell off (at an interesting speed) I discovered that it had cracked well outside the stud PCD at some time in the past ............... then been bronze welded and painted!:rolleyes:

On reflection probably the day before I bought it.
 
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