Air Wrench for changing tyres

John gurgled happily, sounding much like they were saying:

Only if there's one handy.

Yes.

The ratchet has a variable torque setting on it, but in practice it rarely gets used. You just get a "feel".

Depends on how pissed the person holding it is.

I think that I know what you mean when you say tyres you mean wheels

But the 'thoroughly' bit is lost on me

You could always buy some Torque Sticks.

On Tue, 23 Nov 2010 13:51:29 -0800, John waffled:

I have a cheapy impact thing that I use for undoing them.

Air wrenches, yes. I'm not sure the ones in National Tyre are quite the same as the ones used in F1

They're adjustable AFAIK, but the tyre monkeys never seem to care. The place I use always does my wheels up with a torque wrench anyway.

Rob gurgled happily, sounding much like they were saying:

I could. If I cared. Which I don't.

Swapped the wheels on the 900 over the weekend for the winter tyres.

I've got a compressor and windywench at home. I did it at the lockup with the wheelbrace from the boot - and just gave it a bit of oomph.

For home use and for a single vehicle, some real enthusiasts must use and air wrench to change a wheel, but personally I tend to loosen the wheel nuts/studs with a wheel brace/socket and then use an 18v battery drill to remove them.

To I reverse the procedure to replace the wheel nuts/studs and use a torque wrench to tighten them fully.

As for "thoroughly" - most air wrenches will do that.

And are these what they use in Formula One and garages

Yes.

Also, how do you know how much torque you can get

There is a method of adjusting the torque to the correct specification built into the wrench - and they only 'slip' when worn or oversize sockets are used. If you mean do the wheel nuts/studs ever 'slip' - yes they can undo if not tightened to the correct torque, or if the threads are damaged.

With all due respects, if you have to ask such questions for a safety critical procedure, then you may not have enough experience to safely change a wheel and perhaps you should get someone with that experience and knowledge to show you how its done.

Which is correct - over tight nuts cause problems.

Places like you mention have large compressors which build up far more pressure than a home unit(max100psi) so its responsible to ensure the correct torque.

You will find that manufactures do have torque specs for wheel nuts and its there for a reason. Stretched studs, warpped rotors, difficult removal of wheels roadside etc

places that used torque sticks have now swapped over to a real torque wrench, the accuracy over many uses was the problem, while a torque wrench can be re-calibrated the torque sticks have to be thrown away, also the greater distance from the gun could be a problem, especially if you drop the gun :)

snip

Why should a large compressor necessarily build up more pressure? In the motor trade maximum pressures are reasonably constant (say 120 psi) but the larger compressor simply is able to compress more air more quickly and also has a larger storage tank. But higher pressure? No.

My home compressor will get about 120 psi, but it soon runs out of air if I go spraying paint with it.

Rob Graham

In message , TMC writes

I watch most F1 races. They don't always do it thoroughly. :)

Rob Graham gurgled happily, sounding much like they were saying:

Indeed. In fact, most air tools will specify their ideal working pressure

- a quick rummage reveals that for ratchets, it's typically about 6 bar (87psi).

Even a cheap, small compressor such as those being knocked out by the pikeymarkets for £80 or so will have a cut-out set to about 8 bar - which is why they've typically got two outlets, one with an adjustable pressure restrictor.

Adrian explained on 23/11/2010 :

Have you tried giving her some of those pills for the wind?

In message , Harry Bloomfield writes

I've got a book that refers to an H-3 Sea King helicopter as having a

Pressure isn't the issue there, it's tank capacity and the volume of air produced (cfm). Even my 200 litre 16cfm has to work to keep up with a spraygun, but such as DA sanders are even more air-hungry.

I use mine almost all the time for changing wheels. I'm careful with the torque - as someone else said, you get a "feel" - and as my classic Minis are known for snapping the tiny 3/8 studs if you overdo it, I never have.

At my local tyre place a chargehand torques the nuts up - it's a kind of quality assurance - but I've never seen them adjust the wrench and I know my little studs need less than most!

Yes. That's my point.

Rob

air wrenches do not give a reliable/accurate torque, there are just too many variables. Remove the nuts and whizz them up lightly with an air wrench by all means, but then use a torque wrench if possible or arm power with a suitable wheel wrench IF you know what you are doing. Wheels falling off either through too slack or too tight is a real possibility.

Wierdly my DAs fine, I've given in & bougght an HVLP turbine for the spraygun.