Vibration

[cr500dom]

And in automotive it’s all about assembly time.
So if you need an additional locking method, it’ll be preapplied thread lock.
That ensures optimum thread lock for the joint and torque in question, removing the operator from the dosing equation.

 

[Smallfry]

Seen many older engines where the cylinder head has been fitted with replacement flat washers because the originals have been lost or the new ones match and look nicer
Same with brake components. Trouble is, the originals are hard, whereas the replacements are not.

 

[8ob]

Gearbox to engine, car wheel nuts etc. I will assume the bolts of HGVs and buses can work lose? I've seen them plastic pointers that are fitted to each wheel to flag movement.

Its more to do with the settling down of the imperfect mating surfaces between wheels/hub surfaces than the nuts/studs working loose. In the perfect world truck nuts would not need to be re torqued, rust, dirt, paint and imperfect surfaces can take a while to "bed in".

Bob

 

[bricol]

As @PhillipM says its down to cost but also simplicity. It's not uncommon these days to have "special" bolts where a large bolt has a smaller head on it. For some reason they may need a thicker shanked bolt but not done up to a silly torque (or for example if it's going into aluminium). That way the monkey assembling the car doesn't need to know that this 16mm bolt needs torque a and this 16mm bolt needs torque b. 16mm socket means torque a and 14mm socket means torque b.

I think it was on the JLR production line where I saw that torque wrenches had the sockets permanently fixed to them and were fixed at a specific torque. Different head size equalled different torque. Having to add a nord lock into the mix just complicates matters.

I think if they really needed them, they would simply make them captive on the fastener.

 

[Barking Mat]

You're all over thinking this.

I sometimes get clients on boats phoning up as thé have 'vibrations'.

First question, 'are they good or bad vibrations ' then start humming the beach boys.

 

[Erie Fred]

You're all over thinking this.

I sometimes get clients on boats phoning up as thé have 'vibrations'.

First question, 'are they good or bad vibrations ' then start humming the beach boys.

I worked with an engineer that came from a large diesel engine manuf.
He said they had an new engine design installed in a boat for testing (maybe 200-300' industrial boat)
to get some real world time on it.

And it had some vibration problems.....that rattled up thru the framework.

It came to a head when the captain was shaving in his bathroom, and the mirror fell off the wall.

A call was placed to the manuf with the captain yelling "Get this bloody engine out of my boat"

 

[500e]

VW used clamp nuts on Beatles front hubs.
Found on in my box of useful stuff tye other day

 

[PhillipM]

Yep, one fell off the buggy the other month and wrecked the front end. Bloody VW ideas...

 

[cardiffrob]

Dab of weld on the end. Problem solved?

 

[addjunkie]

Dab of weld on the end. Problem solved?

Quite permanent…..far easier just to use a ball pain hammer on the threads!

When I were a lad and we used to tighten big stuff with a hammer, tab washers were the thing! Then they went all new fangled with hydraulic bolt stretching and such!

One issue with just torquing up bolts etc is bolt stretch. You really need to re torque after 45 minutes or so, also allow for the different friction coefficients of the different thread lubricants.