Loose Wheel Nut Indicator

[Dustydog]

Well documented on here about 8 years ago I explained how the rear wheel came loose on the car with caravan in tow.
Mea Culpa. New tyres had been fitted. All wheels torqued up in front of me. BUT I failed to re torque after a few miles. We had driven 4 hours non stop including M74. Once on a 30 mph road we noticed a very weird tremor. Loose change on the centre console was rattling at a high frequency.
We stopped. 3 of 5 bolts were missing the other two loose. Wheel damaged beyond repair.
I'm all for safety but nothing can substitute a torque wrench test before each journey.

 

[emmerson]

Why is it then that I see buses with their big yellow wheel bolt indicators on? Its hard to image bus technicians applying a torque wrench every day rather than a visual check. If a visual is good enough for such vehicles, why can't it be good enough for caravans?

Chris the techies wouldn't do a physical torque check, but they would tap the nuts with a light hammer. A tight nut makes a different sound to a loose one, and the guy's ear would be tuned to the sound, as are mine from many years of nut tapping!
Try it. Loosen one your wheelbolts and tap it with a small light hammer. Then try it on tight one. You'll notice the difference. Don't forget to tighten the one you loosened!!!

 

[chrisn7]

Emmerson I understand what you say - having stripped a classic car to a shell and rebuilt it, including engine and gearbox, I follow such nuances ok. The earlier suggestion of 'sloppy workmanship' on buses is a bit hard to accept given the vehicle usage. I could understand bolts being tightened, and indicator applied, and visual / nut tapping after, but not being left loose and relying on the indicator to show this later.
There has been much talk of elasticity of bolts, strength, high tensile etc, but all this really only applies if all the materials are the same. But they aren't - many wheels are alloy and anyone who has kerbed one will know, they are much softer than steel, so clamping one to the point where a bolt stretches is likely to result in a damaged wheel. Even big blocks of alloy such as cylinder head can distort when bolts are overtightened

 

[ProfJohnL]

......Even big blocks of alloy such as cylinder head can distort when bolts are overtightened

Which is exactly why torque settings should be observed!

 

[JTQ]

so clamping one to the point where a bolt stretches is likely to resul[/u]t in a damaged wheel. Even big blocks of alloy such as cylinder head can distort when bolts are overtightened

If the bolt is not stretched, just like an elastic band, then it develops no tension; here the whole purpose the bolts are used to clamp up the faces and develop the required friction.
I think you are confusing, stretch with permanent stretch into yield, but even some critical bolting does just that with single use bolts, though not our wheel bolts.

 

[Petemate]

I did think of getting some of the indicators, but OH didn't like the idea as they look "gaudy" (her word) However, apart from our wheels having the bolts sunk quite deep in them (needing the deep type of indicators) I always check the torque of them before every trip, both outgoing and returning. I have yet to find any of them needing to be tightened but peace of mind is paramount for me.

 

[Raywood]

A simple way is to paint a thin line across the bolt after tightening running out from the centre of the wheel. This will show any movement but does need a different colour to be used each time the wheel is removed.

 

[PHOENIXFLIER]

Oddly enough, was complimented on my yellow nut indicators by a fellow caravan owner at the weekend "Brilliant idea......why didn't I think of it" was the comment.