is 4over4 the same as 3over3,only wondering, are there any diffrence in the way you change gear,may sound like a stupid question to you guys but not to me,still only a newbie 
Just the same only with less gears
Works the same usually. Some 4 over 4 boxes dont have a range change switch and need to be knocked across to range change.
4 over 4 = 8 gears
3 over 3 = 6 gears
You then have a splitter which splits each gear so you have 16 or 12 respectively.
Its a lot easier than it sounds! if anybody mentions an Eaton twin splitter then run and hide lol!
Similar but not the same.
On a 4 over 4, youāve simply got one switch/button on the gearstick. Usually itās down for low range (1-4) and up for high (5-8); when changing up to high range you simply pre-select the up position, and then depress the clutch and move the gear lever into 5, which corresponds to first in the low range.
Like this;
This is a Scania.
DO NOT try to change ranges by moving the gear lever and the toggle switch at the same time, ALWAYS pre-select it.
With me so far? Good; now, the 3 over 3 is a little bit more complicated, but what youāve effectively got is a second button on the gear lever which gives an overdrive in every gear. So the pattern looks like this, well it does on a Scania anyway;
The lower toggle switch is the ārange changeā same as the 4 over 4, and used in exactly the same way. The top toggle is the āsplitterā which gives you a high and low on every one of the six main gears. Itās set up so that you go up the gears in sequence, unlike the boxes on older trucks, some of them demanded such an intimate knowledge of the ratios that in Fodensā case they were colloquially known as a āChinese puzzleā!
The āCā stands for ācrawlerā which should be self-explanatory and rarely if ever needed.
The splitter is sometimes activated simply by easing the foot off the throttle, and like the range change can be pre-selected.
Thatās the basics of it. In normal use of course you donāt use all the gears every time, but only practice and experience can really help you there.
Oh, and by the way; respect to you for having the good sense to ask. 
Holy s**t. The Eaton Twin Splitter. I remember the first time I drove one of those. I was nearly in tears. No one told me what to do. I was just thrown the delivery notes of the load I was carrying and told to get on with it. I had to work it out for myself out on the road. Eventually I did and to be fair once I had mastered it it was a very easy box to get along with. I must admit that I am not suprised that alot of companies specify autos these days. They donāt want some inexperienced driver destroying their gearbox.
Theyāre fine until you try and go into fourth and end up crunching the gear box by putting it in reverse 
(not that iāve ever done that of course)
If someone gives you an Eaton Twinsplitter give them a big kiss, best 'box ever. Skids keep changing jobs til you get one, youāll see the light and youāll wonder where itās been all your life!
āEatonā manās box, not for ābits of kidsā
Summers were longer & beer was stronger, etc etc
As above keep asking questions Tashman
Cheers Danman
Another question from another relative newbie, what is so weird and wonderful about an Eaton Twin split?? Iāve not yet had the chance to drive a wagon with anything other than a 4 over 4 or straight 6.
thanks for your support all ,i only drive at wekends, or holiday cover /sick etc, normaly auto but, been asked to do work for other company and i no they have scanias,so a bit of forward planning on my behalf 
so thanks again for helping me out,the diagram was spot on thanks,sure i will get it when get rolling 
thanks all,
gnasty gnome:
Similar but not the same.On a 4 over 4, youāve simply got one switch/button on the gearstick. Usually itās down for low range (1-4) and up for high (5-8); when changing up to high range you simply pre-select the up position, and then depress the clutch and move the gear lever into 5, which corresponds to first in the low range.
thanks this will help me,your a star nice diagram lol
Like this;
DO NOT try to change ranges by moving the gear lever and the toggle switch at the same time, ALWAYS pre-select it.
With me so far? Good; now, the 3 over 3 is a little bit more complicated, but what youāve effectively got is a second button on the gear lever which gives an overdrive in every gear. So the pattern looks like this, well it does on a Scania anyway;
The lower toggle switch is the ārange changeā same as the 4 over 4, and used in exactly the same way. The top toggle is the āsplitterā which gives you a high and low on every one of the six main gears. Itās set up so that you go up the gears in sequence, unlike the boxes on older trucks, some of them demanded such an intimate knowledge of the ratios that in Fodensā case they were colloquially known as a āChinese puzzleā!
The āCā stands for ācrawlerā which should be self-explanatory and rarely if ever needed.
The splitter is sometimes activated simply by easing the foot off the throttle, and like the range change can be pre-selected.
Thatās the basics of it. In normal use of course you donāt use all the gears every time, but only practice and experience can really help you there.
Oh, and by the way; respect to you for having the good sense to ask.
Itās a real shame Daisy as theyāre becoming very rare now, I doubt Iāll get the chance again. They had no range change but three splits on each of the four gears making twelve speeds in total. You pre selected each split as you would now but didnāt need the clutch to change. Just lift off the throttle until the revs dropped below a certain point, the split would happen by magic then back on the loud pedal as normal. Changing down youād preselect a lower split then bring the revs up to a certain point and it would change down again by magic. I found it a lovely relaxing way to drive, you canāt rush it.
Thanks babyseal, sounds confusing!! So do you basically select 1st, then go up to 1st and a bit (for want of a better way to describe it!) then 1st and a bit more, then 2nd, 2nd and a bit and so on?
I can manage my nice basic Daf CF 4 over 4, although when I first started driving her the gear box was so knackered, most of the syncromesh didnāt work, you had to double declutch, wait ages between gears and get the revs spot on when changing range or she made the most god awful noises hence her being called Daisy (cos the box was a right cow). I now have a nice new gear box and no nasty noises!
daisydafsdriver:
So do you basically select 1st, then go up to 1st and a bit (for want of a better way to describe it!) then 1st and a bit more, then 2nd, 2nd and a bit and so on?
Perfect way to describe it, it got tricky if you had to slow down quickly then grab a gear to accelerate. The ones I drove sometimes gave a false neutral which wasnāt very helpful on a steep climb although it may have been my driving. I had an old Iveco Eurotech piece of crap with a really tired 4/4 splitter with knock through gate. It sounds like your old box and was a great way to learn how to change by matching the revs and double declutching. Using a newer or rebuilt box was a joy and effortless compared.
baby seal:
daisydafsdriver:
So do you basically select 1st, then go up to 1st and a bit (for want of a better way to describe it!) then 1st and a bit more, then 2nd, 2nd and a bit and so on?It sounds like your old box and was a great way to learn how to change by matching the revs and double declutching. Using a newer or rebuilt box was a joy and effortless compared.
It certainly taught me how to drive her! Quite a baptism of fire to go from a week in a driving school lorry, to a six wheeler tipper with a temperamental gearbox. I managed to nurse it along for over 2 years before it got to the stage of more gears that wouldnāt work than those that would (and the boss to save up for another one ) In a funny way I miss that box, it certainly kept me awake (and stopped anyone else wanting to drive my baby)!
tashman:
thanks for your support all ,i only drive at wekends, or holiday cover /sick etc, normaly auto but, been asked to do work for other company and i no they have scanias,so a bit of forward planning on my behalf
Is it a rigid or an artic?
Rigid is probably a 4 over 4 with range change, ie. 1 to 4 as normal, flick range change up, back into 1st and up to 4th again as these become 5 to 8 with the range change switch up.
If itās an artic, then itās likely to be as depicted above (if itās not auto). Nothing where 1st would be, 1st is in 2nd position etc. Really easy to pick up and in 10 mins after setting off itāll be second nature to you without needing to think about it.
daisydafsdriver:
Another question from another relative newbie, what is so weird and wonderful about an Eaton Twin split?? Iāve not yet had the chance to drive a wagon with anything other than a 4 over 4 or straight 6.
Imagine playing a violin concerto on a fiddle, then the same music on a stradivarius, then you will know the difference between a gear box and an eaton twin split.
Iāve played many a tune on an eaton box! 
truckerjon:
daisydafsdriver:
Another question from another relative newbie, what is so weird and wonderful about an Eaton Twin split?? Iāve not yet had the chance to drive a wagon with anything other than a 4 over 4 or straight 6.Imagine playing a violin concerto on a fiddle, then the same music on a stradivarius, then you will know the difference between a gear box and an eaton twin split.
Iāve played many a tune on an eaton box!
Iām sure Iād be worse!