How do gears/splitters work on a lorry?

[k8_doran]

More closely, how does a splitter work on a lorry? I dont get it, all you do is flick a switch and put the clutch in and they change to the other gears...how does this work?

[sddsddean]

Think of it in the same way as push bike gears. The 1-2-3-4 is the derailleur on the rear wheel and the range change button is the changer on the chain wheel (normally 2 or 3 chainwheels, but assume its 2). By changing the chain wheel you have effectively a complete set of new ratios for the gears on the back wheel. This is in essence how it works, but when you flip the switch on a truck gear lever this works a solenoid which works an air piston which flips the gear ratios. If you have a splitter as well, this works on the same principle, but at the final drive end of the gearbox rather than on all the gears at once. So with a range change and splitter a 4 gear box becomes a 16 gear box. As clear as mud?!

[Clanad]

In addition to the previous clear response... some smaller trucks, as they're called here in the U.S., have a two speed rear end... not unlike some people I know... At any rate an electric solenoid controlled by a switch on the panel shifts the axle drive from a lower rear end ratio to a higher one, in effect giving twice the gear ratios...

[sddsddean]

We don't have them in the UK Clanad(and I don't think any European manufacturers use them) except for US imports.

[Nkakamasembe]

What dont we have in the UK ? people with two speed rear ends!!!!
They are here alright...