The 18spd became popular with the advent of the 1850+ lbs/ft engines.
Carryfast:
robert1952:
You are still assuming that the Fuller/Eaton 'boxes are not pre-selectable. Both Newmercman and I have emphasised that they ARE pre-selectable in recent hours. I simply referred to it as bad practise, not impossible practise. You said: with the ZF type clutch actuated,therefore pre selectable,splitter function. The actuation has nothing to do with whether the splits are pre-selectable or not, for precisely the reasons that Newmercman gave. The Twin-splitter is not everyone’s cup of tea, but it was far too clever a piece of engineering to dismiss out of hand (lest you were thinking of doing so!). Robert
I still don’t get how it’s possible to provide for pre selection of splits ‘unless’ it’s using the ZF type clutch interlock and actuation.
IE in the case of Fuller’s torque sensing idea,like the ZF,the split function is set by the switch.But,unlike the ZF,is then actuated by accelerator movement and resulting torque change,which will obviously inevitably take place before a pre selected split is required so effectively makes pre selection impossible.Which is why it’s ‘bad practice’ in the case of the Fuller but it’s correct practice in the case of the ZF.
The idea of torque sensing splitter actuation seeming even more stupid in the case of the Fuller bearing in mind that they correctly still instruct use of the clutch between split shifts anyway.
You are right in thinking that you can pre-select a Fuller / Eaton split but if you break the torque by backing off the throttle your gear will go through ready or not. I gave 3 reasons (further up the page) why the whole concept of pre-selection was flawed, and you have just reminded me of the fourth reason! 
The constant-mesh ZF operated similarly to the clutch-servo actuated 13-speed Fullers (ie no torque sensitive mechanism). The four reasons for it being rotten practice to pre-select have nothing to do with whether it is ZF or not: the same applies to any lorry with a splitter box, be that constant-mesh or synchromesh. Robert
Carryfast:
robert1952:
Eaton didn’t ‘ditch’ the TS in favour of the 18-speed, CF
. By the late '90s the Twin-splitter had bitten dust quite simply because it failed Euro-3 decibel levels, as I described earlier in the thread. The 18-speeder took off in the States and Antipodes as a natural modern successor to the faithful 13-speeder. Robert
Thanks for correcting that Robert.But the fact remains wherever and whenever Fullers were marketed worldwide to this day it was the 13 speed and 18 speed Roadranger which won out over the TS on the basis of natural selection.On that note personally I think that any box in which splitter function outweighs what’s ‘on the stick’ makes no sense.IE splitter means what it says split the gears available on the stick by two and any more than that and it all gets confusing.Hence the 18 speed and 13 speed are still around but no one really wanted the TS.
I entirely agree with you about the natural selection. The Twin-splitter was just a neat alternative to the four-over-four range-change arrangement, which suited people whose minds work slightly differently and who preferred the TS. Think of it as the Apple of the computer world: in some ways it was a more ‘organic’ gearbox to use than the Microsoft / 4-over-4 range-change!! The Twin-splitter wasn’t so much a better 'box, as a bloody good alternative box. It really comes down to a matter of personal preference, rather than engineering superiority. Robert
robert1952:
It really comes down to a matter of personal preference, rather than engineering superiority. Robert
Maybe that’s the key.While I liked the Fuller for it’s shift quality when I think back it’s always the ZF 12 speed which I think I liked most.IE it suited my preference of driving in being very unforgiving in terms of engine and road speed matching.To the point where it effectively enforced a sequential shift approach and obviously suited my liking for pre selecting splits and good balance between amount of gears on the stick and splits.On that note as I said I think the 18 speed Fuller ‘but’ with clutch actuated splitter would probably be my ideal successor to that in providing the best advantages of both. 
Carryfast:
robert1952:
It really comes down to a matter of personal preference, rather than engineering superiority. RobertMaybe that’s the key.While I liked the Fuller for it’s shift quality when I think back it’s always the ZF 12 speed which I think I liked most.IE it suited my preference of driving in being very unforgiving in terms of engine and road speed matching.To the point where it effectively enforced a sequential shift approach and obviously suited my liking for pre selecting splits and good balance between amount of gears on the stick and splits.On that note as I said I think the 18 speed Fuller ‘but’ with clutch actuated splitter would probably be my ideal successor to that in providing the best advantages of both.
Your post is clearly stated. I entirely understand where you are coming from. I suspect that my preference for the stick-change-for-every-shift 9-speed Fuller strongly echoes your preference for a constant-mesh 'box in which you are compelled to make conventional gear changes. Nowt so strange as folks, eh? (I reckon if the old 5-over-5 range-change Scania box had been constant-mesh and as good as a Fuller, I’d have remained faithful to the V8 142/143 but I can’t rewrite history! 
) Robert
I hated that ZF 12spd, had it in my first artic, a 2800 Daf and then later in a 2032 Merc and a 2300 Daf, a truly awful thing.
newmercman:
I hated that ZF 12spd, had it in my first artic, a 2800 Daf and then later in a 2032 Merc and a 2300 Daf, a truly awful thing.
Yes, I used it in Merc 1626 artics and it was pretty grim and very exacting 
, but I do recognise that it required a doggedly consistent driver to make it work and I suspect that CF falls into that category. I can understand, too, why he would prefer a modern 18-speed Fuller that didn’t have splitter gears that simply melted into place (as they do), but rather stayed where they were until you dipped that clutch! It wouldn’t suit me (or, I suspect, you NMM!), but each to his own, eh. 
. Robert
Without wishing to sound harsh, running up and down the M1 in a relatively high powered unit with a light load on a night trunk is hardly a true test of the character of a gearbox.
Robert, like yourself and most others contributing to this thread, I’ve stirred a stick in far more challenging conditions, in those circumstances the lightning fast shifting characteristics of anything from Eaton Fuller wins every time in my book.
My preference is for the 18spd, I find the ability to go up a gear and a half makes for smoother progress than the 13spd and with the high, flat torque available at low rpm, the 9spd doesn’t fit very well as you need to take it up to 1800 or so ready to drop down to 1200 for the next gear. I know you could shift at 1600 and drop to 1000, but in severe terrain, or with a heavy load you need that 200rpm cushion for the turbo to spool up and give strong boost.
With an older pre electronic engine the 9spd was perfectly adequate and a 13spd was unnecessary and could even hurt performance and economy unless it was used carefully, in the older lorries especially and even today in my Volvo with 13spd, I seldom split a gear going down the box, unless I only need half a gear to get over a hill, other than that I go down full gears and only split going back up the box.
I have never used a twin splitter either but they sound very similar in operation to the Foden 12 speed to me? They were simple enough, however like the 13 speed Fuller I had if you preselected early and hit a bump in the road it would change itself anyway! I found it better to change down whole gears when tackling hills, on some I used to go from top and miss a few out altogether on the Fuller nine and thirteen speed, on one local drag out of Ashbourne I would keep in top as long as possible then drop it straight down into sixth or even fith when the revs had dropped right off which was better than changing down through each gear as I lost less speed, and then use the split option for climbing them. When running empty you didn’t really need the splitter at all anyway.
Pete.
newmercman:
Without wishing to sound harsh, running up and down the M1 in a relatively high powered unit with a light load on a night trunk is hardly a true test of the character of a gearbox.Robert, like yourself and most others contributing to this thread, I’ve stirred a stick in far more challenging conditions, in those circumstances the lightning fast shifting characteristics of anything from Eaton Fuller wins every time in my book.
My preference is for the 18spd, I find the ability to go up a gear and a half makes for smoother progress than the 13spd and with the high, flat torque available at low rpm, the 9spd doesn’t fit very well as you need to take it up to 1800 or so ready to drop down to 1200 for the next gear. I know you could shift at 1600 and drop to 1000, but in severe terrain, or with a heavy load you need that 200rpm cushion for the turbo to spool up and give strong boost.
With an older pre electronic engine the 9spd was perfectly adequate and a 13spd was unnecessary and could even hurt performance and economy unless it was used carefully, in the older lorries especially and even today in my Volvo with 13spd, I seldom split a gear going down the box, unless I only need half a gear to get over a hill, other than that I go down full gears and only split going back up the box.
Yes, all that makes sense to me. And I do (did) exactly as you describe in your last paragraph, only dropping a half to clear the occasional short summit, and otherwise lugging down to the next whole shift. Robert
little question was a twin splitter ever put in a daf 2800 ?
fredm:
little question was a twin splitter ever put in a daf 2800 ?
Im not that tecnical but I think the Dafs were ZFs & as a driver of an eaton Ts I liked them & Ive never heard as much drivel here in the last few pages as Ive ever heard in over 40yrs of sitting in transport caffs.
fredm:
little question was a twin splitter ever put in a daf 2800 ?
I’ve never heard of one with one. 2800s had either ZF 12-speed or Fuller 13-speed. Then when the 2800 DKSE came out the Continental ones had ZF synchro boxes and the UK version was given the 9-speed Fuller. Robert
cheers for that mate its just that I went out with a mate many years ago in his 2800 for a day I was at a loose end and he let me drive for a couple of hrs and I certainly played some tunes on it much to his disgust he was a yorkeshire man so didnt pull any punches , sadly long passed but a great fella, the memory is not what it was just thought I would ask
yes they were mnv 931v had one and so did a few at BRS rental loads hated them but once mastered were the best
just flicked through this thread and thought would add what I was taught…I have driven 13 & 18 speeds over here in canada. for the class 1 test you had to double clutch and sequentially change in high range and full shifts in low even coming up to lights etc …what a pain driving through cities that is especially given how heavy the clutches are over here lol.
my new job entails driving a new classic peterbilt 18 speed and the fleet mechanic (and owners son) is peterbilt time served. they showed me the best method for longevity and ease of driving for shifting.
this will probably not make sense to most (if any lol) but here goes… basically it is floating up etc but when going down instead of just revving to match and then to some degree hoping/ guessing the rpms are right, instead pull the gear out hold the rpms and then you gently offer up to the next lower gear and then increase revs and it sweetly pulls the gear in, it sounds like u haven’t revved up to a passenger and have just moved the lever through the gate and it can be done so so quickly ,gently and no force. i never miss a shift with it and i haul moving fluids in a 53 foot tanker in terrible uphill double back steep grades and go off road too. this method also allows me to block shift effectively too sometime two or more full gears a hit as you have not enough time/ would lose to much momentum sequentially shifting and get stuck, particularly in spring thaw mud…
also the mechanice said eaton told them on a factory visit double clutching is primarily aimed at novices (like explained in ts manual earlier) and can actually do more harm in the real world due to inadvertently engaging the clutch brake slightly on bumps etc, higher likely hood of using more force to get into gear if just slightly mismatched on full shifts (especially with fluids) , cause jerks in driveline and are also more likely to miss judge rpms due to fatigue especially at the end of a 13 hour (legal lol) drive…
one of the older guys also showed me that high range crawler is useful when bobtail and wanting to burn cars off from lights etc making it actually a 20 speed transmission but that’s another story…
BTW I only briefly drove a ts in the UK I thought it was great and needed a skill that all added to being a professional…dumb down a job enough and this is not possible and attracts some wrong mindsets imho
That downshifting method is pretty much how I do it, not necessarily using the slight crunching to find the sweet spot, but gently slipping it into gear with a slight adjustment to rpms if necessary. I also go onto the throttle very delicately, as if it has an egg on it and I don’t want it to break as this also helps to make the shifts smoother.
Hi rsg, do you use the clutch pedal whilst on the move?
hi
no I don’t use the clutch when moving now and find for some unbeknown reason enjoy truck driving a bit more as a consequence…bizarrely a little bit akin to when you first learn to ride a bike without stabilizers on perhaps I dunno , …I also find it a bit of a wierd paradox in that something that requires more applied driver thought imput and in my experience, extra personal application and involvement (I’m no super trucker by any stretch) , than say using amt I shift, in reality makes me more attentive (rather than some may claim preoccupied) to reading road conditions, potential situations further up ahead etc in order to attain safe, smooth progress with just enough shifts as necessary.
I’m sure, and have sadly witnessed frequently, that too many guys may see the detachment/ freedom I shift can bring, as simply a tempting/ easy opportunity to be spent distracted on phones, rooting in bags on the floor etc i accept some may probably do the same with a manual…but they would have to be even more reckless to do so which I would hope should narrow the margins somewhat …btw I’m not saying all amt drivers here !. I know there are some firm, and ever increasing, advacates of amt’s who are no doubt more experienced/ safety concious drivers than me do nothing of the sort !
I guess the old adage no one size/ solution fits all maybe rings true…
I am with you on amt, vehicles I now work with all seem to have amt boxes and in my opinion they have all lost their soul, I would love to be able again to drive a lorry which has a gear lever and clutch pedal used only for setting off, yes I know I am a bit of a dinosaur but these new fangled lorries bore me. I actually use the manual option in our DAF’s wherever I can & strangely enough I feel the motor runs better whilst using less revs getting up to speed.