How many gears in a Roadranger truck gearbox?

The most common type of Roadranger gearbox has 18 forward speeds and 4 reverse speeds. However, older trucks might have 9, 13 or 15 forward speeds and you can identify them by the style of the gearstick.

Roadranger ‘boxes are non-synchro and also called ‘crash’ ‘boxes, based on the sounds they make if you get the gear change wrong. It’s important to learn how to use the gearbox gently otherwise significant expensive damage can occur. You can do this using a Roadranger gearbox course.

Let’s ignore the leftmost positions (R and LO) for the moment and deal with the main forward speeds. You can see the positions 1, 2, 3 and 4 which are also doubled with 5, 6, 7 and 8. This is a logical sequence that you’ll follow when changing up or down. This is often called an H pattern.

Range change

At the basic level, you change from one to four, then switch the range change lever on the front of the gearbox to high range, then continue using the same positions for 5, 6, 7 and 8.

The process is the same when coming down through the gears – when you want to change down from 5 to 4, flick the range change to lo range. That gives you 8 gears in total – what about the other 10?

The splitter

Each gear can be split into L and H (often called direct and overdrive). Your main gear position is L or direct. Using the grey splitter button on the side of the gear stick, you can move from 1L to 1H which is like a half-step between 1L and 2L.

Now we know that each gear position has a L and H split, we have 8×2 gears for a total of 16 gears. This is an 18-speed, though, and the final two gears are in the LO position.

Crawler gear

LO is the crawler gear for very slow manoeuvres, where you are starting off with a very heavy load or if you have rough ground and a difficult load (e.g. forestry work). These crawler gears move the truck along at walking pace or less. LO gear only works when the range is in lo range and there are the two splits, as per the other gears.

Reverse

We’ve covered our 18 forward speeds, now let’s look at reverse. There are four reverse speeds in an 18-speed Roadranger: lo range L and H (direct and overdrive) and hi range L and H. You should not change the range while driving in reverse. The lowest reverse gear is a crawling speed gear, while the highest reverse gear is for when you need to reverse a longer distance at a higher speed, for example, if you don’t have a trailer connected.