76 replies to this topic

[Cooperman]

No - you don't! The large nuts are done up as tightly as you can with a 4 ft pole on the T bar - and then ON to the next split pin hole. Way beyond the range of most torque wrenches. As for the disc-hub bolts - just be sensible when tightening them

Just buy a bigger one, we have some at work that go up to about 800 lbs/ft after that we just use torque multipliers.

Where possible, a torque wrench should always be used. It doesn't take any extra time that using a normal ratchet and then you know the job has been done correctly with no undue stress to any nuts/threads.

So, are the torque figures quoted for Minis for dry or oiled/wet assembly? The difference can be over 25%. Do these figures apply to new, old or all threads? These figures are meaningless without that basic piece of data. In the Aerospace Industry torque settings are part of a total assembly procedure which includes type of assembly lubricant, or lack of it. Then again, should you torque up, slacken by one full turn and re-torque, or not? This must all be specified and adhered to if torque settings are to have any meaning.
I've always used a torque wrench on dry assembled engine bolts/nuts and on oiled APR bolts/nuts, but almost never on anything else and I've been preparing minis for competition for 49 years with no problems connected with torque settings. It's not rocket science. All you need is one tiny spot of oil or grease on a thread and the torque setting may not be tight enough, which is far worse than just doing them up to what common sense says is correct.

[Carlos W]

But what common sense says is tight enough may not be tight enough! Yet another thread which has turned into a debate and not really answered the original question

[998dave]

So, are the torque figures quoted for Minis for dry or oiled/wet assembly? The difference can be over 25%.

I'd argue 25% of a known figure is much better then 25% of an unknown. Just because you can't be absolutely 100% correct doesn't mean you shouldn't try tog et as near as possible.
Torque figures are always on clean dry threads unless otherwise stated.
Normal manufacturing tolerances in the aut industry today run to about 15%, so you might tighten an M10 bolt to 47.5 +/- 7.2 Nm, for example.

This is still much better, and much more controlled then tightening until you're having to use one arm at arms length on an 18" ratchet.

Back to the OP question, the correct answer is that you should buy and use a torque wrench.

Dave

[Silentbob]

There are 3 settings for most mini nuts/bolts.

T

FT

and ofc

RFT

[Cooperman]

And you think that 'Mr. Average Mini-Fixer', working in his home garage is going to have all new, clean, dry threads at all times. Coming from an Aerospace background I am very fussy about cleanliness, but even I dont use new bolts every time.
If you don't use new and clean and completely oil-free bolts/nuts every time, the torque settings are meaningless. In fact, an old and oily thread could be well below safe tightness even though the torque setting was adhered to and the torque wrench was within calibration time (every year if used regularly). Some quoted torque figures are very low if applied to old and oily threads which equals unsafe in reality.
Well, I'll continue to do it the way I have, safely, for almost 50 years, knowing the tightness (note the word) is safe and reliable.

[Guess-Works.com]

Well I'm absolutely gob smacked....

Never in the years I've been associated with this forum have I read such idiotic, irresponsible and quite honestly dangerous advice on a any single topic...

Gone are the days of passing good practice knowledge onto younger members.

[Shifty]

Well I'm absolutely gob smacked....

Never in the years I've been associated with this forum have I read such idiotic, irresponsible and quite honestly dangerous advice on a any single topic...

Gone are the days of passing good practice knowledge onto younger members.

Guessworks does have point, lets not forget that some of the people reading this won't have anything like the experience of some of the members posting up here.

If you were teaching an apprentice straight out of school you'd show them the absolute correct way of doing things, no matter what practises you've evolved over the years.

On safety critical items such a brakes or suspension using a torque wrench that will give a quantifiable reading is with out a doubt the best way of doing it for a novice.

I know that I'd be happier travelling in the OPs car if I knew that he'd used one!!

[mini93]

If you don't use new and clean and completely oil-free bolts/nuts every time,

why would you need to use new bolts, the idea of torquing them is to bring the bolt into its elastic region, if like you say, the threads were oiled you wouldnt bring it into that region and there for the bolts still wont need replacing as they wouldnt have been stretch.

well...if a jobs worth doing its worth doing right, and while i can still happen to use my hands to correctly bring my torque wrench to the right point ill continue to do so, at home and at work

[998dave]

And you think that 'Mr. Average Mini-Fixer', working in his home garage is going to have all new, clean, dry threads at all times. Coming from an Aerospace background I am very fussy about cleanliness, but even I dont use new bolts every time.
If you don't use new and clean and completely oil-free bolts/nuts every time, the torque settings are meaningless. In fact, an old and oily thread could be well below safe tightness even though the torque setting was adhered to and the torque wrench was within calibration time (every year if used regularly). Some quoted torque figures are very low if applied to old and oily threads which equals unsafe in reality.
Well, I'll continue to do it the way I have, safely, for almost 50 years, knowing the tightness (note the word) is safe and reliable.

Two points really here;

1) Repeatedly saying you're working in the aerospace industry, while relevant, doesn't neccessarily mean your infallible. I've a pair of degrees, am a Chartered Engineer, and have enough years of experience in Turbochargers and high pressure common rail systems, (arguably the two most intricate parts of any car), to be able to talk knowledgably.

2) Mr average mini fixer, isn't going to have perfect threads everytime, but he is able to clean them, you still seem to be arguing that as you can't get within very tight tolerances there's no point even trying?

The correct answer is always that tightening with a torque wrench to as close to the specified torque as possible is the right thing to do. Surely you're not going to try to argue against that?

Dave

[dale.lavender]

Thanks for the thread title 998dave, iv'e read this with interest but what 998dave, shifty and guessworks have said makes sense to me and i've decided to hold off and buy my self a decent torque wrench (im not saying anyone is wrong or right i think i prefer things by the book thats all)
Could anyone recommend a decent torque wrench to buy (as i have no clue what all the numbers mean)
Thanks again
DL

[Dolly 89]

after reading this im glad you have said that i always use one and will continue to do so theres nothing worse than doing a simple job and stripping the threads inside and needing to get i re threaded and also it will be the closest you will get to the correct torque setting of the bolt and the thread

[Ethel]

I have to admit I don't use a torque wrench on things like disc bolts, but I readily accept it's best practice, especially if you're new to spanner monkeying. I would torque front hubs - not because it's critical to get it accurate but because it's so tight it's hard to judge when you're hanging off it with all your might.

I've always accepted torque values as being "dry" unless stated otherwise: the higher friction means you won't stretch the bolts in to yield, as you could tightening a lubed thread to a dry value.

It depends how the fastener is loaded as to whether replacing them is worth considering. Something like a disc bolt that's mostly loaded in shear will be ok, I'd think about replacing nuts & bolts cyclically loaded in tension, especially as big ends.

Even a £10 ebay special will be better than no torque wrench. £50 will get you a good'n - with a test certificate.



Surely "heated" topics like this are what a forum is good for. But there must also be a responsibility for those of us offering advice to explain when we're giving advice that isn't by the book.

[me madjoe 90]

Teng 1/2" Are cheap and reliable.

[Darkscamp]

I've got a Halfords Pro torque wrench and in 'tests only blokes would do', it was more accurate than the same age snapon one my mate has.

[Spud_133]

Is this a bad time to say when I was changing the head on my car my dads friend, with at 30 years expirence in the trade, done my spark plugs up with a nut gun!