Thursday, March 30, 2017

It's True, I'm All Torque...

And old school.
I'm trying to work out when I became old school. I guess I was brought up with old-fashioned methods of working on vehicles and there comes a point when you become the same as the person who taught you. Who knows? 
I also owned old, classic bikes when I was first able to ride on the road so my path was probably set.

What does this have to do with anything?
I often get asked about the torque settings on my various blog posts. Especially the little KTM Adventurer. The truth is, I don't know the actual values required by KTM and I generally crack on through with experience. And this stuff can only be learned over time. When I first started as an apprentice, every time a sump plug was tightened by me, it was double-checked by an old-school mechanic. Every single time. And this went on until they'd decided I was doing an alright job (yeah, they're still checking).

Of course, there are set values for most components and in this day and age of blaming someone else, stupidity and a lack of common sense, manufacturers have to give you an absolute figure for every bolt. Because they don't want to hear you whinge but, more importantly, don't want to be held accountable for anything.

In this crazy world, no longer can you keep tightening a bolt until the thread strips, and then back off half a turn. (Please don't do this, I'm being sarcastic)

Hand tight, and torque wrenches.
With all this frivolity I've forgotten what I was writing about. 

Oh yes, I was considering the small bolts like M5's and M6's a lot of home mechanics consider to be as strong as a 10.8 M12 Allen bolt. Having said that, I've seen a few "professional" mechanics do the same. There is a very fine line when tightening a camshaft cap, for instance, before the threads pull straight out of the head. Ask a Vauxhall/Opel mechanic about the 16V engines and they should be able to give you a fair indication. 

You see, you're looking for that sweet spot where it "feels' just right. You know at that point to stop dead. No further, or tears will flow. But on those Vauxhall cylinder heads, something appears to be made of case-hardened cheese. Either the alloy is very soft, or the bolts just keep stretching. Either way, it always feels like you've left them loose. But you haven't.

And mechanics needed to know. How tight do we go? The official consensus was hand-tight. Most of us, with just a hint of common sense, could get by with that. I wasn't looking for extra grief. I've been tightening bolts for years with very few issues.

But no!
Just as there is always someone in your class, when doing a manufacturer's course, that has to ask the obligatory stupid question, along comes old mate wanting to know how tight is hand-tight? 

"Well, how tight do you think hand-tight is?" asks the lecturer.

"Well, it's different for everybody. What if you're a big bloke, or a female apprentice?" retorts the mechanic (soon to be beaten to a pulp by a class full of impatient technicians).

Stalemate. Yes, everyone's idea of hand-tight is different. But give me strength! 

I see their point, but if you have to ask how tight to tighten a bolt to hand tight, are you in the right job? 

The answer.
Well some clever person at Vauxhall had a think and came up with a figure, which might've been around 5.9NM (I forget), and across the land everyone was happy. No more stressing out over loose bolts, stretched bolts, or case-hardened cheese bolts. 

Those of us with common sense rejoiced because that was one less stupid question that would keep us at the college longer than necessary.

For a while at least.
Because with that came a new problem altogether. You see, no one had needed a torque wrench that could work so accurately, and at such a low figure, before. And where the hell do you get one anyway? Oops. 

So what did old mate, who couldn't decide how tight hand-tight actually was, do without the mouse-sized torque wrench?

He went back to the old method of doing the small bolts up to his idea of hand-tight. Just like in life, the answer was there all along. 😜

More soon folks...