Carryfast:
robert1952:
Punchy Dan:
carryfast-yeti:
some proper gearboxes there 
just got my son in law a job at my place (all Daf auto’s)…i’d love to hear him playing a few tunes on those 'boxes 
There are enough muppets that cant even make a nice change on a synchromesh.
Stood on my local roundabout waiting for someone this week and listened to the cars negotiating it. I came to the conclusion that it must be National Pick A Gear Week! Robert
Probably the two best driver instruction videos available. 
youtube.com/watch?v=8hKKzOHRTPY
youtube.com/watch?v=yU26_YNK9vA 4.12 -
That first video was shot about 5 miles from where I live (Auckley). Anybody know who the fella is and if he and the truck are from Hatfield woodhouse? I’d love to go take a look at it.
I thought he was on here but can’t remember his username.
viewtopic.php?f=35&t=54395&start=3960#p2340725
Firstly Fuller’s introduction of a Twin Countershaft design was arguably just a case of adding to the already inherently better ability of a straight cut gear train.Not because of the idea that straight cut supposedly has less ability to transmit torque than helical which would go against all the accepted consensus which I’ve known.
As for the noise issue probably more like the EU just looking for an easy reason to put the constant mesh Fuller out of the frame.Also bearing in mind the wholesale move to synchro types across the board including ZF.Maybe more likely to have been the result of safety fears among the jobsworths of drivers missing gears on mountain decents.As I said an answer to the question,at least why no option of a manual version of an I shift based transmission,in addition to the withdrawal of other constant mesh options from ZF and Spicer might answer that question.While the fact that the manual constant mesh Fuller is still alive and kicking in North America probably answers the question as to the superiority of the strong and simple to maintain straight cut constant mesh gear train Fuller v synchro types.Or for that matter the choice between I shift etc v just trusting the driver to get on with the job they are paid for. 
viewtopic.php?f=35&t=54395&start=3960#p2340832
As I said a synchro and helical gear train with the synchros stripped out. 
Whether that was all about weight is open to question bearing in mind the other advantages of shift speed and lighter actuation of the shifts with resulting lower loads on the actuation system.
As for the Fuller they introduced multi mesh straight cut gear trains in their transmissions more than 30 years ago and while the I shift seems to have some formidable potential torque input figures in its range the 18 speed Fuller isn’t exactly a no hoper in that regard.Being seemingly able to more or less match all except one of the six I shift options in that regard.
This is taken from the Fuller RT-610 manual and describes the principle of the Roadranger gearing. The second paragraph tells how the gearbox manages to cope with the torque demand. There is a difference between interpreting the ability to transmit torque between spur (straight cut) and helical (angle cut) gears between efficiency and capability (strength).
Helical gears are less efficient as far as losses between what goes in and what comes out because of the energy consumed due to their sliding contact. However they are able to withstand the loading imposed upon each tooth better than a spur gear because there is a greater area of tooth, or in fact teeth, in contact at any one time, ie the tooth is longer and the area of more teeth is on contact.
In order for the spur gear to match this it is necessary to increase the area of tooth in contact. This would mean increasing the length of the tooth and thus the length of the casing or coming up with some other idea. The Roadranger solution was first to double the number of layshafts (countershafts) and later to increase the number of teeth on each gear.
To do this second option the gear diameter has to be greater, the shaft diameter smaller or the individual teeth slightly smaller. Since making the gear diameter greater requires a wider or taller casing, the thickness of the teeth was reduced and the number of teeth increased.
For the same tooth size and equivalent width (thickness of the gearwheel), helical gears can handle more load than spur gears because the helical gear tooth is effectively larger since it is diagonally cut.
cav551:
This is taken from the Fuller RT-610 manual and describes the principle of the Roadranger gearing. The second paragraph tells how the gearbox manages to cope with the torque demand. There is a difference between interpreting the ability to transmit torque between spur (straight cut) and helical (angle cut) gears between efficiency and capability (strength).
Helical gears are less efficient as far as losses between what goes in and what comes out because of the energy consumed due to their sliding contact. However they are able to withstand the loading imposed upon each tooth better than a spur gear because there is a greater area of tooth, or in fact teeth, in contact at any one time, ie the tooth is longer and the area of more teeth is on contact.
In order for the spur gear to match this it is necessary to increase the area of tooth in contact. This would mean increasing the length of the tooth and thus the length of the casing or coming up with some other idea. The Roadranger solution was first to double the number of layshafts (countershafts) and later to increase the number of teeth on each gear.
To do this second option the gear diameter has to be greater, the shaft diameter smaller or the individual teeth slightly smaller. Since making the gear diameter greater requires a wider or taller casing, the thickness of the teeth was reduced and the number of teeth increased.
For the same tooth size and equivalent width (thickness of the gearwheel), helical gears can handle more load than spur gears because the helical gear tooth is effectively larger since it is diagonally cut.
That’s all fair enough.But however the multi mesh idea is achieved it obviously results in a net gain in spreading the load across more gear tooth size or there would be no point in doing it while also busting the myth that straight cut gears can only mesh against a single gear at a time.While you’ve over looked the axial loadings through the gear train created by helical cut gears v zero in the case of straight cut.In addition to the easier maintenance advantages.The end result being a transmission which can more or less handle just about any torque input you can throw at it while being unarguably much easier to fix if/when it does eventually break.
Although as I said that doesn’t mean the I shift doesn’t seem to have a formidable ultimate torque input capacity.Although I’d guess with a similar formidable cost to fix it when it does eventually need to be rebuilt/replaced.Which probably explains why the old school Fuller is still alive and kicking when customers are given the choice away from the EU jobsworth meddling.Not to mention when building something which can handle heavy race/performance car duty ideally it’s best to chuck out the helical synchro standard gearbox and replace it with a decent constant mesh straight cut gear box.Whick,like Fuller,is why Hewland is still alive and kicking.
Yes the blindingly obvious axial loadings created by helical gearing and the necessity for containing that thrust with a stronger casing and different bearing type than necessary in a spur box. I had been waiting and waiting for that to get a mention. The weight advantage of a potentially lighter casing of course being a reason why straight cut gears are favoured in motor racing.
Fuller’s designers were thinking of something else as well so what was it?
cav551:
Yes the blindingly obvious axial loadings created by helical gearing and the necessity for containing that thrust with a stronger casing and different bearing type than necessary in a spur box. I had been waiting and waiting for that to get a mention. The weight advantage of a potentially lighter casing of course being a reason why straight cut gears are favoured in motor racing.
Fuller’s designers were thinking of something else as well so what was it?
As I’ve said I’d guess a potential torque input capacity of well over 2,000 lb/ft,excellent driving characteristics,and arguably relatively lower maintenance and purchase costs for the performance resulting from the keep it simple design ethos of the gear train,probably covers all the bases ?.
Which just leaves the question of the purchase and rebuild costs of the I shift for comparable torque input capacity and any weight advantages of straight cut v helical possibly being a bonus ?.
I drove some of the early SA400 model with RR Eagle 220 naturally aspirated engines.
Splendid truck in its day,at least compared to what went before.
The gear change was unusual in that 1st was right and back, 2nd was straight forward , 3rd , left and forward, and 4th left and back, button up and back through the upper four. It was a pattern known in Scotland as “arse about face”, but after a wee while you got used to it and like all these gearboxes, once you were rolling, the clutch was redundant . The nine speed was good, but the thirteen speed was probably the best of all .
The Fuller Roadranger gearbox was developed at a time when multi speed transmissions were required to cope with the comparatively narrow rev band of useful torque produced by the American made diesel engines of the day . Fuller wished to incorporate the extra ratios obtainable with twin stick designs which normally operated separately mounted transmissions, or booster boxes as they were called in the UK, into just the one assembly.
The designers needed to cater for the then foreseeable increases in input torque likely to be required. This focused attention on the combined limitations of spur gears, tooth loadings, and particularly the radial loadings which adding additional gear clusters to what would seem to mean ever lengthening shafts and casings. Straight cut gears and a single layshaft design looked like dictating that each gear was going to have to be thicker to reduce the tooth loading, and there were going to be more sets of gears added to the shafts. The extra shaft length was likely to cause problems with the radial load imposed on the shafts unless something was done. They could adopt the same solution which the UK’s David Brown used and utilise a horizontally split casing with an intermediate bearing and corresponding webs in the casing, or they could come up with something different.
They chose to place the mainshaft between two layshafts, so doubling the number of teeth in contact, reducing the tooth loading and allowing the thickness of the gears to be reduced. The mainshaft, being sandwiched between the two layshafts, was itself no longer under radial load and although the casing was still subject to all the radial loading, that resisted by the each layshaft and its bearings was halved. The bonus was that not only were they so far saving length, but also weight since components could be reduced slightly in dimensions. The lack of any need for bushes for the mainshaft gears to run on, allowed more weight to be saved by employing dog clutches which mated with internal teeth in the mainshaft gears, rather than the more common external designs in common use.
The need for additional ratios was dealt with by what was effectively a repetition of the main box primary gear train, but this time with a synchroniser and dog clutch enabling through drive or reduction drive via a gear train. The second stick was replaced by an air system operating the hi-lo range selector.
There were two versions of this design one for an input torque of around 600 lbft and a larger version for around 950 lbft. For torque ratings beyond that a significant level of upgraded parts were required which does in some instances include helical gearing for the auxiliary section; generally indicated by the figure 7 as the third digit in the model code.
cav551:
The Fuller Roadranger gearbox was developed at a time when multi speed transmissions were required to cope with the comparatively narrow rev band of useful torque produced by the American made diesel engines of the day . Fuller wished to incorporate the extra ratios obtainable with twin stick designs which normally operated separately mounted transmissions, or booster boxes as they were called in the UK, into just the one assembly.
The designers needed to cater for the then foreseeable increases in input torque likely to be required. This focused attention on the combined limitations of spur gears, tooth loadings, and particularly the radial loadings which adding additional gear clusters to what would seem to mean ever lengthening shafts and casings. Straight cut gears and a single layshaft design looked like dictating that each gear was going to have to be thicker to reduce the tooth loading, and there were going to be more sets of gears added to the shafts. The extra shaft length was likely to cause problems with the radial load imposed on the shafts unless something was done. They could adopt the same solution which the UK’s David Brown used and utilise a horizontally split casing with an intermediate bearing and corresponding webs in the casing, or they could come up with something different.
They chose to place the mainshaft between two layshafts, so doubling the number of teeth in contact, reducing the tooth loading and allowing the thickness of the gears to be reduced. The mainshaft, being sandwiched between the two layshafts, was itself no longer under radial load and although the casing was still subject to all the radial loading, that resisted by the each layshaft and its bearings was halved. The bonus was that not only were they so far saving length, but also weight since components could be reduced slightly in dimensions. The lack of any need for bushes for the mainshaft gears to run on, allowed more weight to be saved by employing dog clutches which mated with internal teeth in the mainshaft gears, rather than the more common external designs in common use.
The need for additional ratios was dealt with by what was effectively a repetition of the main box primary gear train, but this time with a synchroniser and dog clutch enabling through drive or reduction drive via a gear train. The second stick was replaced by an air system operating the hi-lo range selector.
There were two versions of this design one for an input torque of around 600 lbft and a larger version for around 950 lbft. For torque ratings beyond that a significant level of upgraded parts were required which does in some instances include helical gearing for the auxiliary section; generally indicated by the figure 7 as the third digit in the model code.
We know from examples like the evil shifting ZF Ecosplit,or in house Merc alternative ?,that a helical synchro gear train isn’t mutually exclusive with an all integral multi ratio range change and splitter type box.So that obviously wasn’t Fuller’s main motivation in going for/staying with the twin counter shaft straight cut constant mesh option.The fact remains that they first and foremost rightly chose that option with an unarguably far better result in terms of shift quality and lower maintenance costs resulting from that far simpler and inherently better,in terms of axial loadings,gear train design.
Which unsurprisingly is still obviously able to compete against what seems like the best shot constant mesh helical gear train design used in the I shift.In which case as I said the cost of a factory exchange 18 speed Fuller seems to be in the region of $15,000.As opposed to ? $ in the case of the I shift ( or even Eco Split in real terms in the day ) as a figure doesn’t seem to be easy to find.Bearing in mind that there’s no reason to think that even by today’s standards the Fuller would be any less durable in service than the I shift and possibly even moreso bearing in mind the added simplicity of not having all the automated control systems to bother about.While the heavy,slow shifting synchro Euro options like the Eco Split etc were never a realistic contender in that regard v the Fuller anyway.Which is why it took some typically dodgy EU regulations to put the Fuller out of the frame in Euroland.
robert1952:
Dieseldog66:
The Seddon Atkinson had the double ‘U’ pattern , same as the Crusader if they had the 9 speed Fuller, but they were not backwards like the early DAF 2800.
I’m curious now! I didn’t know the early 2800s had a 9-speed Fuller. I knew the Continental ones had a 13-speed Fuller (drove one). I also knew the later DKSE 2800 model had a 9-speed Fuller (UK version only - Continental version had a ZF synchro) (drove one). Robert
Sorry Robert, the Daf in question did not have the Fuller 9 speed, it was a ZF , but you changed up from right to left, I should have made that clear at the time of posting.
IIRC the Seddon Atkinson 300 used the ZF AK 6 80 and had a conventional shift pattern. Seddon certainly seemed to have made a better job of the linkage than DAF did becasue having driven both it was a much easier beast to handle in the Seddon. Once you had figured out what to do it first to get the lid off, it was quite a nice box to work on too. IIRC the turret was the most troublesome part.
Dieseldog66:
robert1952:
Dieseldog66:
The Seddon Atkinson had the double ‘U’ pattern , same as the Crusader if they had the 9 speed Fuller, but they were not backwards like the early DAF 2800.
I’m curious now! I didn’t know the early 2800s had a 9-speed Fuller. I knew the Continental ones had a 13-speed Fuller (drove one). I also knew the later DKSE 2800 model had a 9-speed Fuller (UK version only - Continental version had a ZF synchro) (drove one). Robert
Sorry Robert, the Daf in question did not have the Fuller 9 speed, it was a ZF , but you changed up from right to left, I should have made that clear at the time of posting.
No probs old mate! Actually, I drove a Merc 1626 with a frack-to-bunt ZF box. It was a six-speed pattern with a splitter on each = 12. Cheers! Robert
ERF-NGC-European:
No probs old mate! Actually, I drove a Merc 1626 with a frack-to-bunt ZF box. It was a six-speed pattern with a splitter on each = 12. Cheers! Robert
It was the constant mesh ZF AK 6-90 that was put in the lower powered options of the early DAF 2800’s at least.With the 9 speed Fuller in the later 2800 ATI.The AK 6-90 was arguably the only credible Euro alternative to the Fuller,having particularly liked its all splitter operation and the extra gears compared to the 9 speed Fuller.
While it seems to have been the 13 speed Fuller which was the standard fit in the DAF DKS and from seemingly incorrect memory the 3300.When information shows that it was the typical Euro synchro Eco Split which was the standard fit in the 3300.
While ironically,like the I shift,the AK 6-90 seems to have been another single counter shaft helical gear train design ? and also from memory a lot less forgiving than the Fuller in it’s shift characteristics but,with the exception of the later DAF 85/95 box,still in a different league to the usual Euro synchro offerings especially the evil nasty 6-80 in the 2500,or the Merc 1628 let alone the even worse 2534 boxes.
Not sure if I’m off topic here but fairly sure one of you can answer
I’ve been told that the Foden 12sp box was an original design,was it a ground breaker or well used mechanics?
Also when it was on the drawing board why didn’t somebody point out the convoluted shift pattern, compared to most boxes, and more importantly do something about it? re Eaton twin splitter. Go steady with me I’m a mechanical half wit. Cheers Paul
Especially for CF the auxiliary section of a Fuller RTLO 147-13A. The most highly stressed part of the gearbox. Note especially the type of gear used. I have not listened to the commentary.
youtube.com/watch?v=3JwlPFvAZ2g
Coomsey, I expect Windrush is your man on this. I have some ancient Foden 'box manuals including the 5 speed which I’ll look at this evening. There are mnay different 12 speed sequences depending upon whether it was an overdrive or underdrive box and the individual ratios.
cav551:
Coomsey, I expect Windrush is your man on this. I have some ancient Foden 'box manuals including the 5 speed which I’ll look at this evening. There are mnay different 12 speed sequences depending upon whether it was an overdrive or underdrive box and the individual ratios.
Thanks Cav. God help me I’m lost already
cav551:
Especially for CF the auxiliary section of a Fuller RTLO 147-13A. The most highly stressed part of the gearbox. Note especially the type of gear used. I have not listened to the commentary.
youtube.com/watch?v=3JwlPFvAZ2g
The straight cut v helical gear argument certainly seems to contain some contradictions.With numerous previous ‘heavy duty’ examples of the Fuller box actually containing a straight cut auxiliary section.
youtube.com/watch?v=C2RCVSLBJ0Y
While the latest 18 speed versions certainly states a move to a helical auxiliary for reasons of both noise reduction and ‘durability’. In which case the obvious question in that case is why not move to a single counter shaft totally helical gear train like the I shift which certainly seems to have an ultimately higher torque input capacity than the Fuller.
Having said that it would be interesting to find out exactly what’s going on here and possibly why ?.
youtube.com/watch?v=Vg4eJKqc41E 3.45-3.59
In addition to the question as to why the AK 6-90 at least seems to have been a helical constant mesh geartrain,except for 1st gear being straight cut ?.Or for that matter examples of after market performance car applications examples of an all straight cut gear train except for over drive top ?.
