robert1952:
It was new Euro decibel regs that killed off the fitting of Twin-splitters back in the late 2000s ! Robert
No it was not, just not enough customers. Sisu still uses Fuller, DAF can be had with same 18 sp, I think they dont have straight cut gears anymore.
Yes it was. However, it was in the late '90s not the late 2000s as I stated. I wrote a piece for T&D magazine at the time. The 18-speed Fuller you mentioned is a much newer, more modern 'box and I believe it is more compliant with the EU regs and I think Foden carried on fitting them after the demise of the Twin-splitter here. Robert
Your spot on Robert we were big twinsplitter users with all ERF E and EC series being fitted with them unfortunately they were discontinued due to EU noise emissions
The last lorry to be fitted with the twinsplitter was a SA Stratocruiser owned by an owner driver from the Cornwall/Devon
Thank you. Yes, it was Euro 3 regs the TS didn’t pass. I was very disappointed as it was one of my favourite gearboxes! You’ll see a part of the piece I wrote about its demise on the first post of this thread. Robert
Punchy Dan:
I’ve not seen a 18 speed in a foden , would the difference be that it’s 16 speed with crawler ?
Hello Dan. No they were deffo 18-speed Fullers, same as used in Oz and USA trucks. Here’s some evidence for you! Right click on the image to read the small print. Robert
Cheers Robert , I hope it was a stronger box than the 16 speed eaton , Punchards had a 4455 with a eaton 16 speed later replaced with the much better 13 speed fuller but it seams strange how it didn’t have the 18 speed from new .
Had the Twin-splitter in both these, the Strato was mine for 7 years, 325-Rolls engine & I loved it, up/down through the box like a knife through butter, I would happily have her back tomorrow . Our 411s had the same box, it was still great box but it had a different shift/feel through the hand in the 411, but you could still kick 'em along ! Use the clutch-brake to hurry the shift through on up-hill down-shifts & they were both good working tools! Chris
If you read modern instruction manuals for Fuller installations in US trucks, they make it clear that the clutch-brake is only to be used for engaging your pulling away gear without crunching or clunking! However, as many of us who used to drive theses machines know, that mechanism was used, and encouraged to be used, to effect fast upshifts, especially when going uphill. Pat Kennett certainly advocated its use in his truck tests for TRUCK magazine. At least, in England!
With the Eaton Twin-splitter this was most certainly still the case even in more modern times. I owned an Iveco Eurostar with a Twin-splitter and I used to use the inertia-brake (as it’s sometimes called) to good effect. At almost ten years old it still had its original clutch in good condition when I got rid of it.
I’ve just found the driver’s manual for it among my souvenirs and it says:
‘Your gearbox is equipped with an inertia brake which reduces the number of revs of the lower secondary shaft in order to assist upward gear changes. it can only be operated by depressing the clutch pedal to its maximum. The final result is a swift adjustment in the speed of the shafts linked to the clutch, and therefore an instant engagement of the preselected ratio.’
It then goes on to caution the user never to do this for downshifts. I sometimes wonder if it was drivers trying to downshift using this technique who shortened the life of clutches, not the upshifters as is sometimes claimed to be the case!
robert1952:
If you read modern instruction manuals for Fuller installations in US trucks, they make it clear that the clutch-brake is only to be used for engaging your pulling away gear without crunching or clunking! However, as many of us who used to drive theses machines know, that mechanism was used, and encouraged to be used, to effect fast upshifts, especially when going uphill. Pat Kennett certainly advocated its use in his truck tests for TRUCK magazine. At least, in England!
It then goes on to caution the user never to do this for downshifts. I sometimes wonder if it was drivers trying to downshift using this technique who shortened the life of clutches, not the upshifters as is sometimes claimed to be the case!
Fuller’s own instructions in the day available on Youtube,which I’ve posted elsewhere,suggest that clutch brakes were meant to be used to save the time of having to wait for the input side of the box to slow down when putting it into gear from neutral.With just the usual double de clutching procedure to slow down the input shaft speed for upshifts shown and no further reference to clutch brake use.
As for downshifts why would anyone possibly think that they’d need to slow down the input shaft for downshifts when that contradicts the fact that downshifts require the total opposite to upshifts in speeding up the input side of the box to match the lower gear to the road speed. While it would probably also be likely to cause more transmission damage than just the clutch brake.
robert1952:
If you read modern instruction manuals for Fuller installations in US trucks, they make it clear that the clutch-brake is only to be used for engaging your pulling away gear without crunching or clunking! However, as many of us who used to drive theses machines know, that mechanism was used, and encouraged to be used, to effect fast upshifts, especially when going uphill. Pat Kennett certainly advocated its use in his truck tests for TRUCK magazine. At least, in England!
It then goes on to caution the user never to do this for downshifts. I sometimes wonder if it was drivers trying to downshift using this technique who shortened the life of clutches, not the upshifters as is sometimes claimed to be the case!
Fuller’s own instructions in the day available on Youtube,which I’ve posted elsewhere,suggest that clutch brakes were meant to be used to save the time of having to wait for the input side of the box to slow down when putting it into gear from neutral.With just the usual double de clutching procedure to slow down the input shaft speed for upshifts shown and no further reference to clutch brake use.
As for downshifts why would anyone possibly think that they’d need to slow down the input shaft for downshifts when that contradicts the fact that downshifts require the total opposite to upshifts in speeding up the input side of the box to match the lower gear to the road speed. While it would probably also be likely to cause more transmission damage than just the clutch brake.
Because they haven’t read the manual / been trained for that gearbox (didn’t happen in those days) / or were accustomed to synchro-boxes. Robert
dave docwra:
Clutch was only there for pulling away and stopping, never used it whilst on the move with mine…
This is not the case, as I’ve just shown. However, this still begs the question: why was it encouraged with some Eaton/Fuller constant-mesh twin-layshaft 'boxes and discouraged in others. Robert
EDIT
Ha! I’ve found evidence for the correct use of the clutch-brake for fast upshifts, as usual in the works of Pat Kennet in his book, ‘Better Driving’. I have scanned the pages for you. Click on images to magnify. Robert
There’s an obvious flaw in that idea Robert.The limiting factor in upshifts is matching engine speed to road speed whereas with downshifts road speed is matched first.Therefore upshifts are all about matching the input side of the box to the lower engine speed for the higher gear which can’t be done before the engine speed has first reduced and stabilised at the correct speed ‘before’ the matching takes place.By that logic it seems obvious that using a clutch brake,to slow down the input side,will in most cases just create a mismatch by slowing down the input side of the box faster and therefore ‘before’ the engine speed has decayed to the correct speed for the higher gear.In which case it might work in the case of a race car engine designed to lose engine speed very quickly between upshifts but not so good in the case of something like a big 14 litre ■■■■■■■■■■■ idea of double de clutching upshifts in that case being all about firstly de clucthing it then waiting for and allowing the engine speed to fall to the correct level first and only ‘then’ matching the input side of the box to the lower engine speed by re engaging the clutch in neutral.The idea of trying to match the input side of the box to road speed decay being a red herring in that case bearing in mind that it still won’t help in the case of road speed decaying faster than engine speed where engine speed is falling slower.
IE it’s how fast the ‘engine speed’ falls,together with close enough ratio steps to not need it to fall very far,which is the relevant issue regards upshift speeds nothing to do with the input side of the box and a clutch brake won’t fix the former.
In which case the suggestion contained in Fuller’s instruction regards engine brake use with trucks at least seems spot on.Probably to the point where a double de clutched upshift will still create at least a more accurate match,if not faster,than using the clutch brake even on something with a relatively fast fall in engine speed like the Detroit.Which probably explains why even in the case of acceleration testing of the Bedford TM from memory we still didn’t use the clutch brake other than putting in gear from neutral.
There’s an obvious flaw in that idea Robert.The limiting factor in upshifts is matching engine speed to road speed whereas with downshifts road speed is matched first.Therefore upshifts are all about matching the input side of the box to the lower engine speed for the higher gear which can’t be done before the engine speed has first reduced and stabilised at the correct speed ‘before’ the matching takes place.By that logic it seems obvious that using a clutch brake,to slow down the input side,will in most cases just create a mismatch by slowing down the input side of the box faster and therefore ‘before’ the engine speed has decayed to the correct speed for the higher gear.In which case it might work in the case of a race car engine designed to lose engine speed very quickly between upshifts but not so good in the case of something like a big 14 litre ■■■■■■■■■■■ idea of double de clutching upshifts in that case being all about firstly de clucthing it then waiting for and allowing the engine speed to fall to the correct level first and only ‘then’ matching the input side of the box to the lower engine speed by re engaging the clutch in neutral.The idea of trying to match the input side of the box to road speed decay being a red herring in that case bearing in mind that it still won’t help in the case of road speed decaying faster than engine speed where engine speed is falling slower.
IE it’s how fast the ‘engine speed’ falls,together with close enough ratio steps to not need it to fall very far,which is the relevant issue regards upshift speeds nothing to do with the input side of the box and a clutch brake won’t fix the former.
In which case the suggestion contained in Fuller’s instruction regards engine brake use with trucks at least seems spot on.Probably to the point where a double de clutched upshift will still create at least a more accurate match,if not faster,than using the clutch brake even on something with a relatively fast fall in engine speed like the Detroit.Which probably explains why even in the case of acceleration testing of the Bedford TM from memory we still didn’t use the clutch brake other than putting in gear from neutral.
The flaw that you find is on paper, CF: the fact remains that the practice was widely used in its day and I can assure you that it works. It’s not a thing you need to do very often with a Fuller / Eaton 'box; after all, you can effect most upshifts on the flat very quickly by not using the clutch at all. If in doubt you’d always upshift by double-declutching without the throttle blip. But if you are going uphill and want to effect a super fast change without losing vital momentum, the practice described by Pat Kennett is spot-on and it most certainly works once you’re good at it. I suppose it’s just one of those effective, if unorthodox, tricks of the trade; like using the exhaust-brake to effect quick changes. We live in a black, white and grey world in which nothing is ever absolutely right or wrong . Try it with a 14-litre Iveco lump and you’ll have no problems. Robert the Twin-splitter
just to chip in , i had S9JCB in here the other day, absolute mint and i mean MINT , ERF EC M11 380 8 wheeler collecting a dumper, complete with twin splitter, its on the JCB demonstration fleet , now the outside is spot on , the inside looked like it came out of sandbach a couple of weeks ago. got to give JCB their due, they had converted this from a tanker to a beaver tail , and that motor was literally like new inside and out. driver had to prise me out of it.
and where’s my phone, charging in the bloody office again.
robert1952:
…you can effect most upshifts on the flat very quickly by not using the clutch at all. If in doubt you’d always upshift by double-declutching without the throttle blip. But if you are going uphill and want to effect a super fast change without losing vital momentum, the practice described by Pat Kennett is spot-on and it most certainly works once you’re good at it. I suppose it’s just one of those effective, if unorthodox, tricks of the trade; like using the exhaust-brake to effect quick changes. We live in a black, white and grey world in which nothing is ever absolutely right or wrong . Try it with a 14-litre Iveco lump and you’ll have no problems. Robert the Twin-splitter
What’s the ultimate fast upchange method, do you think? No clutch at all and decompression brake? Did I not read somewhere that some Jake brakes can be set/programmed to come on when the the accelerator pedal is released, above a certain engine speed?
robert1952:
…you can effect most upshifts on the flat very quickly by not using the clutch at all. If in doubt you’d always upshift by double-declutching without the throttle blip. But if you are going uphill and want to effect a super fast change without losing vital momentum, the practice described by Pat Kennett is spot-on and it most certainly works once you’re good at it. I suppose it’s just one of those effective, if unorthodox, tricks of the trade; like using the exhaust-brake to effect quick changes. We live in a black, white and grey world in which nothing is ever absolutely right or wrong . Try it with a 14-litre Iveco lump and you’ll have no problems. Robert the Twin-splitter
What’s the ultimate fast upchange method, do you think? No clutch at all and decompression brake? Did I not read somewhere that some Jake brakes can be set/programmed to come on when the the accelerator pedal is released, above a certain engine speed?
I always thought the pre select then put the lever in to neutral and then back into the gate was the quickest way for a good up shift but that’s in my own personal experience
you are correct in that, i had a foden alpha and the fitter programmed the computer so that the jake came on automatically when i took my foot off the accelerator . it was great to drive , on long downhill stretches just tickle the pedal to keep the jake off , lift off the pedal and the jake came on . dave
i see you were a fan of bunny hopping the twin splitter gazsa . i used that method whenever i needed a quick upshift , you had to learn to be smooth doing it so as not to ■■■■■■ at the transmission . dave
rigsby:
i see you were a fan of bunny hopping the twin splitter gazsa . i used that method whenever i needed a quick upshift , you had to learn to be smooth doing it so as not to ■■■■■■ at the transmission . dave
@ Rigsby and Gaza: with you both all the way there! The ‘bunny hopping’ method was pretty bomb-proof. The ‘bunny hopping’ method was perfect for the splitter changes, but the clutch-brake was better for the stick changes. Robert
The jake is best when used at the drivers discretion via the left foot ,those micro switches and the Rev generator switch on the pump are a waste of time ,my Foden is on auto and works well with the sincromesh box ,my ERF is on a floor switch only I fitted it that way ,the Ec I drove prior had the jake on auto and with the twin splitter took some getting used to as you needed to keep your boot on the throttle slightly to stop the jake cutting in when gear changing ,i don’t know if the time delay can be changed as it was in so quick it ■■■■■■ sometimes when changing gear .
i think you come into the proper driver class though dan , we were given these things to drive and worked out the best use for ourselves . it was part of the interest in the job for me , getting the best out of whatever lorry i was allocated . dave
! Robert
Robert
. Our 411s had the same box, it was still great box but it had a different shift/feel through the hand in the 411, but you could still kick 'em along 
when that contradicts the fact that downshifts require the total opposite to upshifts in speeding up the input side of the box to match the lower gear to the road speed. 
While it would probably also be likely to cause more transmission damage than just the clutch brake.
