i had this box fitted in a f90 man and a erf,the erf set up was by far better than the man,the ■■■■■■■ motor seemed better suited to the gearbox than the mans motor did,never missed a down change on the erf,but it was always pot luck on the man.still loved the box though.
I really liked the eaton twin split gearbox once i got the hang of it,i drove several erf’s with this box fitted but i found that the instalation was better in some trucks than it was in others.
Passed my test at 11 am - and by 2pm was on my way into the city of London (Barbican) in an E10 325 with twin split with 24 tonne of plasterboard to be off loaded by hand- thats one sharp learning curve 
I must be weird cos i got the hang of judging the revs/roadspeed with a twin split pretty quickly and in a day or two was bunny hopping the gears happily both up and down the box- once you got the hang of it the clutch brake became irrelevant
The above comments are totally correct the linkage setup in ERF’s was vastly superior to Fodens and Seddons cable arrangement the Strato set up in particular was particularly dire, and ruined a good gearbox
used twin splittter in ERF E & EC trucks , also in a troner cabbed seddon strato thought they were good boxes & would be to anyone who had at least a half decent idea of how they worked although , i’ve met old hands with 10-20 years more experience than me who just didn’t get it & hated the box , each to their own i suppose the 9 speed road ranger was also a mystery to same as well , although again not a box i had any problems with .
a few years back on this forum 6-7 years maybe the general concensus was (even before the wide useage of auto’s) the twin splitter was dropped because of the ever increasing horsepower of truck engines & it wasn’t up to the stresses of torque being put through them & the move toward more electrical systems.
Auto’s were about obviously , but as i daresay a few drivers here will remember the less than reliable original offerings from scania & volvo but it was only going to be a matter of time before the twin splitter & the like were to be edged out by new technology , i know some real drivers here are fighting it but it’s called progress 
I remember when Sainsbury’s were selling some very elderly ERF units (I think that they were well over 15 years old).
I asked who bought them and why, and was told that the main customers were fairground operators who loved them for their fibreglass cabs and the virtually indestructible gearboxes.
CALUM:
I really liked the eaton twin split gearbox once i got the hang of it,i drove several erf’s with this box fitted but i found that the instalation was better in some trucks than it was in others.
That was much the problem with the installations
Fodens cable system was not perfect although if well adjusted it could be tolerated. Sudden Accidents were generally clunky
Loved the twin split. Once you got used to it there was nothing finer. You could do a main gear change(up and down) without the clutch too
I haven’t read the rest of the thread. has anyone mentioned the semi automatic twin splitters on the M A N’s? They took some getting used to 
First paid job in a truck was a Turbostar Iveco 320 pulling milk tanks with the twin splitter in it . Big learning curve after being taught to drive in a Volvo F7 with a syncro box in it . First two days with the boss in the passenger seat trying to teach me how to drive it left me wondering if I could do the job or had I made a huge mistake . Third day I was sent out with one of the other lads as it was a quiet day . Rather than try to teach me to drive it by double clutching it he showed me how to match the speed and revs - 10 minutes later I’d just about got the hang of the thing and after that I really started to get along with it . Empty at a set of lights there wasn’t another truck on the road the same HP that could keep up with you - preselect and blip the throttle and you just kept going . I was given a new EC10 380 and nearly turned it down because I had to clutch for every gear change in it - 4 over 4 with a splitter .
Loved the twin split but I also like the fuller 10 speed when your thum got strong enough to use the splitter
Bah! 
Rose tints again. It was a pain in the arse in all honesty, though worked well enough I suppose once you got the hang of it…
Give me a decent auto box every day…easier the job is the happier I am…!
Fetched a Foden S108 from Charnwood Trucks for a customer once - after noting the three-position Eaton-Fuller gear lever and cab window sticker showing a twin splitter was fitted, drove up the M1 making all sorts of noises…
… after a while it dawned on me that a Fuller 13 speed was fitted, not the twinsplit. Made enquiries back at the yard to be told that 8 legger had had a second hand cab fitted, obviously from a wagon with a different gearbox