Anyone got any advice on these, how they work and if its gonna be easy/quick to pick up how to use 'em?
Thanks peeps. 
wtf is a roadranger gearbox some fancy name on something weve been using for 20 years more info.
Eaton Roadrangers are 13 speed constant mesh trannys based on a 4 over 4 range change, but with a splitter on high range as well. So you have the basic 1-2-3-4 switch pole 5-6-7-8 but, on 5-8, you have a second switch position for the half gear split. You may have 2 switches instead of a 3 way switch, though. One is the range change, the other the splitter.
Once you have gone 1-4 and have flicked the switch to high range as you pass through neutral into 5th gear, you can then flick the button again and ease off the throttle and it will select 5 1/2, then for 6th, you pull the shifter back and flick the switch back to engage 6th, then you have a split on there so can flick the button forwards again… and on up to 8 high.
Clear as mud, right?
However, there is also and 18 speed roadranger which simply has a split on all gears. This one will always have seperate switches, generally one on the front of the shifter for range and one on the side for splits. If it is a 13 speed then you will not be able to put the range switch into low while the splitter is in high, with an 18 you will.
General rule of thumb is 400 rpm for a full shift and 200 between splits. Depending on the engine type as to how fast the engine revs to how fast you have to be and to how interesting they can be to handle.
A point of interest, Eaton always said you could use the range change and splitter on the crawler of a roadranger so you had 2 cheater gears.
a eaton spliter 
Not really. My 81 Daf even called it a roadranger… But it was dutch.
the first time you try to drive one it looks confusing, after about 5 mins you should get the hang of them, i was quite fond of the foden that had one in it that i had for a bit.
bobthedog:
Not really. My 81 Daf even called it a roadranger… But it was dutch.
its an EATON u git
Weeeeeeellllll…
Nope… Being a true pedant I have to disagree. It’s an Eaton Fuller… Over there they call it an Eaton, while a fuller is when you switch drinks with your mate after last orders.
Over here it is a Fuller, while an Eaton is a snobby school.
Doesn’t matter really, it’s a 13 speed gearbox with a knack to it. Not sure I prefer it to the old 9 speeds but it certainly is a good box.
If I remember correctly you could change gear without using the clutch or was that just me showing off
It was a Fuller Road Ranger. designated 11609 or 11613 in the UK
Guess the difference
Give me an Eaton over an auto any day
Tiger.
Fastrantiger:
Give me an Eaton over an auto any dayTiger.
ill second you there, best gearbox i have used
doesn’t sound like the Roadranger box I had in big J with Rolls royce Eagle engine.
The only strange thing about that was that instead of a conventional H pattern for the gears 4th and 5th (9 +10) were transposed.
If I remember correctly, so I probably don’t.
The RoadRanger gear stick looks exactly the same as a Twin Splitter stick, with the same 3 position switch on it. Thats the later box. The earlier ones had two switches I believe.
With the RoadRanger you have low range with the switch all the way back,
standard gear change 1 through to 4.
Then you put the switch all the way forward for High Range - Low split.
Middle position is High Range - High split.
Gear position 1 gives you 5 n 6 in high range.
2 gives you 7 n 8
3 gives you 9 n 10, and strangely enough
4 gives you 11 n 12 
PRE-SELECT the switch position, BEFORE easing off on the throttle to change gear.
You use the gears in standard patterns, 2 or 3 to pull away, block change full gears until weight or slope dictates using the half gears.
Other than pulling away and stopping, you should be able to rest your clutching foot.
If you prefer, you can clutch every change though.
To begin with I’d recommend using all the gears, all the way up and all the way down. Once you learn to judge your revs right for getting half gears, judging full gear revs gets a lot easier.
There are a few tricks, to get changes to go in quickly, but the main thing to learn is, when changing gears GIVE IT TIME. Try to ■■■■■■a change in a hurry and the only gear you’ll find is neutral. You’ll get to play some … unusual tunes 
, until you get it.
If at all possible, see if there’s someone who can take you out for a quick demo and practice. Half an hour should be plenty to get you started on the right lines. After that it’s just practice.
Even after years of practice, you’ll find the gear box will call you names occasionally, especially if your tired.
These boxes are like Eaton Twin Splitters in another way. They are a box you either Love or Hate.
I’m another one who loved the Eaton Twin Splitter; a fantastic box, once you get used to it 
del949:
doesn’t sound like the Roadranger box I had in big J with Rolls royce Eagle engine.
The only strange thing about that was that instead of a conventional H pattern for the gears 4th and 5th (9 +10) were transposed.
Sudden Accidents and ERF were opposite to each other even though the engine gearbox and axles was the same â– â– â– â– â– â– â– / Fuller / Rockwell setup
my 1983 peterbilt 359 has an underdrive eaton,apparantley very popular in the usa.it’s a dog leg h shift pattern with splitter on low range only.once high range is selected the splitter switch is locked.that with the 355 rear diffs gives a very high top speed…so someone told me
regards andrew
Admit to being a bit confused as to what a Fuller Roadranger box actually is after reading these posts.
I know for a fact that the box in the GUY BIG J was a Fuller Roadranger because it said so on the selector housing, that was a nine speed , with a button operated clutch brake.
At least one of the boxes described above is what I would call an Eaton 13 speed box as fitted to Transcontinentals among others, .this is the 4+4+split with the 3 position switch on the stick,( looks similar to twin split).
Although some describe it as a Roadranger I never heard it described as such when driving them. (Usually bolted onto â– â– â– â– â– â– â– 355).
I know what an Eaton twin split is having driven ERF 's/ Leylands with them so am not confusing these with Fullers.
I guess from the OP’s question however he isn’t asking about the nine speed one!
13 speed
18 speed
theres a couple of ways to drive the roadrangers, personally id reccomend using the clutch, although often i dont myself, when taking off make sure you fully depress the clutch for a few seconds to engage the clutch brake so you can get your gear, then after that you only need to dip the clutch slightly, not even halfway for your changes, double clutch, dip to get it out and dip again to get it back
alternatively you can float the transmission by getting your revs right and it should just slip out, adjust the revs again and slip it back in, the nobodys gonna be able to tell you on a forum how to do it, you’ll figure it out though, dont worry too much if it crunches now and again, its called a CRASH box 
this might help .
Theres a post on extinct gearboxs on the oldtimers forum gives you some clues 