What gearbox did those BigJs have? I read somewhere that the later ones had
fullers,yet on here,many say the Gardner/Fuller combination didn’t really work?
Kev73:
What gearbox did those BigJs have? I read somewhere that the later ones had
fullers,yet on here,many say the Gardner/Fuller combination didn’t really work?
All our Big J’s had the 6 speed AEC/Thorneycroft boxes,the Seddons had the David Brown 6.600 boxes.We did have one A Series ERF with 180LXB with the Fuller 609 box and it was a great little motor and was able to outperform the Guys and Seddons because of it’s more and better gearing.Cheers Bewick.
Kev73:
What gearbox did those BigJs have? I read somewhere that the later ones had
fullers,yet on here,many say the Gardner/Fuller combination didn’t really work?
Hiya at Harrisons of Stoke we had a ERF (MEH118K) 180 with a 9 speed fuller it was a good motor
the other’s 180’s had Brown boxes with Eaton 2 speeds. sometimes the 2 speed was slow in cold weather.
all the 240 Gardner’s had fuller boxes.I think the later GUY’s had bigger engines so that where the fuller
came into use. they also had a clutch stop on the gear leaver next to the high/low range change.
John
a clutch stop on the gearlever?
Kev73:
a clutch stop on the gearlever?
They had a push button clutch brake on the gearlever to slow the mainshaft when selecting a gear whilst stationary otherwise it would go in with a crunch ! Most motors with a constant mesh box had the clutch brake in the bottom travel of the clutch pedal.
Trev_H:
Kev73:
a clutch stop on the gearlever?They had a push button clutch brake on the gearlever to slow the mainshaft when selecting a gear whilst stationary otherwise it would go in with a crunch ! Most motors with a constant mesh box had the clutch brake in the bottom travel of the clutch pedal.
Hi Trev. The button idea for the clutch brake seems better to me than the bottom-of-the-clutch pedal one. It must have made for quicker gearchanges than fully depressing then releasing the clutch pedal (or just waiting for the revs to decrease between gears).
AHA! i knew of the clutch pedal operated brake,i was told about how to use those,but on a switch sounds a better idea to me,although maybe not so when moving the gearlever at the same time?
[zb]
anorak:Trev_H:
Kev73:
a clutch stop on the gearlever?They had a push button clutch brake on the gearlever to slow the mainshaft when selecting a gear whilst stationary otherwise it would go in with a crunch ! Most motors with a constant mesh box had the clutch brake in the bottom travel of the clutch pedal.
Hi Trev. The button idea for the clutch brake seems better to me than the bottom-of-the-clutch pedal one. It must have made for quicker gearchanges than fully depressing then releasing the clutch pedal (or just waiting for the revs to decrease between gears).
You was only supposed to press it for selecting gears when stationary, if you used it a speed you would wear the brake out quick, with the fuller box the changes were lightening fast anyway not at all like the awful thornycroft 6 speed with which you could roll a smoke inbetween changes.
The fuller box seemed really suited to the Gardner 180, for some reason the gearstick was a lot shorter in the gardner motors compared to the ■■■■■■■ and Rolls and if fitted with the W pattern box, in the forward position overdrive top meant that it was more comfortable to sit with your leg to the left of the stick otherwise the range switch dug a hole in the side of your knee, you really had to be a contortionist to drive the J’s. 
It was ■■■■■■■ or Rolls for me everytime, you never had a heater with the Gardner !
Trev_H:
You was only supposed to press it for selecting gears when stationary, if you used it a speed you would wear the brake out quick, with the fuller box the changes were lightening fast anyway not at all like the awful thornycroft 6 speed with which you could roll a smoke inbetween changes.
I get it it now- using the brake to slow the engine and the input shaft together would cause more wear to the brake. Putting it at the bottom of the clutch pedal travel is better, because it means that the mass of the rotating parts of the engine would be disconnected from the input shaft. Was it normal to use the exhaust brake to slow the engine more rapidly, when changing up the gears, IE stamping on that and leaving the clutch alone altogether?
I only ever used the clutch to pull away and when coming to a stop, with the revs right you could change fast without it.
[zb]
anorak:Trev_H:
You was only supposed to press it for selecting gears when stationary, if you used it a speed you would wear the brake out quick, with the fuller box the changes were lightening fast anyway not at all like the awful thornycroft 6 speed with which you could roll a smoke inbetween changes.I get it it now- using the brake to slow the engine and the input shaft together would cause more wear to the brake. Putting it at the bottom of the clutch pedal travel is better, because it means that the mass of the rotating parts of the engine would be disconnected from the input shaft. Was it normal to use the exhaust brake to slow the engine more rapidly, when changing up the gears, IE stamping on that and leaving the clutch alone altogether?
As Trev_H says clutch brakes are only used when selecting a gear from neutral while stationary.You wouldn’t want to use the exhaust brake when making clutchless changes or even release the accelerator completely because that puts the engine and transmission into an overrun situation which won’t allow deselection of the previous gear.With clutchless changes you need to lift just enough to create no load at all either overrun or load through the transmision so you can then slide it out of gear into neutral easily then while it’s in neutral you match road and engine speed and then slot it into the next gear.Regardless of what many say though clutchless changes are not by the book.
However doing it by the book every change should be double de clutched and in my experience double de clutched changes were always faster anyway because the accelerator can be released completely on upshifts as soon as the clutch is released when taking it out of gear and putting it into neutral between changes which brings the engine speed down faster ready for the higher gear.The same applies when putting it into neutral ready for a downshift as that can be done faster by declutching the transmission first than by trying to balance the accelerator input to make sure that the transmission is neither under load nor overrun before putting it into neutral ready for the shift.
Carryfast:
As Trev_H says clutch brakes are only used when selecting a gear from neutral while stationary.You wouldn’t want to use the exhaust brake when making clutchless changes or even release the accelerator completely because that puts the engine and transmission into an overrun situation which won’t allow deselection of the previous gear.With clutchless changes you need to lift just enough to create no load at all either overrun or load through the transmision so you can then slide it out of gear into neutral easily then while it’s in neutral you match road and engine speed and then slot it into the next gear.Regardless of what many say though clutchless changes are not by the book.However doing it by the book every change should be double de clutched and in my experience double de clutched changes were always faster anyway because the accelerator can be released completely on upshifts as soon as the clutch is released when taking it out of gear and putting it into neutral between changes which brings the engine speed down faster ready for the higher gear.The same applies when putting it into neutral ready for a downshift as that can be done faster by declutching the transmission first than by trying to balance the accelerator input to make sure that the transmission is neither under load nor overrun before putting it into neutral ready for the shift.
As you lift off the accelerator, the torque will decrease from forward to reverse. As it passes through zero, the load on the gears will be zero, so the gear can be disengaged with light load on the lever. This works with dog-engagement and synchro boxes. Keeping some pressure on the accelerator will just slow the process down, as will pumping the clutch pedal like a tart. If you have some finesse, you can do perfectly smooth, clutchless changes, even on a synchro 'box. The Volvo I-shift applies the engine brake as soon as a gear is disengaged, so it “arrives at” the correct speed for the next gear up more quickly.
Every post on this forum, relating to gearchanging on a constant mesh 'box, says not to use the clutch. It must have been a frustrating experience, sitting in the passenger seat of a vehicle when you were driving it.
Here’s the clutch brake and range change on the 9 speed Fuller in a Gardner 180 powered Big J
fryske:
Here’s the clutch brake and range change on the 9 speed Fuller in a Gardner 180 powered Big J
I bet there was a temptation to palm that button, when changing up, especially with a 6-speed 'box! 
Foden’s instruction in the use of the clutch brake was to depress the clutch pedal half way, move gearlever to neutral, and then fully depress the pedal and engage the gear. In practice it was as quick to double declutch, or as one of our driver’s used to do, keep the engine revs constant (dont release the throttle when in neutral) and feed the gear in when everything was at the right speed which gave a beautiful smooth change either changing up or down the box. Took a good deal of practice though and I never fully mastered it like he did! 
I used to use the clutch to disengage the gear and then drop it in clutchless otherwise the splines used to wear badly in the Fuller boxes due to the drag factor, the Foden cable gear change didn’t help matters much.
Pete.
[zb]
anorak:Carryfast:
As Trev_H says clutch brakes are only used when selecting a gear from neutral while stationary.You wouldn’t want to use the exhaust brake when making clutchless changes or even release the accelerator completely because that puts the engine and transmission into an overrun situation which won’t allow deselection of the previous gear.With clutchless changes you need to lift just enough to create no load at all either overrun or load through the transmision so you can then slide it out of gear into neutral easily then while it’s in neutral you match road and engine speed and then slot it into the next gear.Regardless of what many say though clutchless changes are not by the book.However doing it by the book every change should be double de clutched and in my experience double de clutched changes were always faster anyway because the accelerator can be released completely on upshifts as soon as the clutch is released when taking it out of gear and putting it into neutral between changes which brings the engine speed down faster ready for the higher gear.The same applies when putting it into neutral ready for a downshift as that can be done faster by declutching the transmission first than by trying to balance the accelerator input to make sure that the transmission is neither under load nor overrun before putting it into neutral ready for the shift.
As you lift off the accelerator, the torque will decrease from forward to reverse. As it passes through zero, the load on the gears will be zero, so the gear can be disengaged with light load on the lever. This works with dog-engagement and synchro boxes. Keeping some pressure on the accelerator will just slow the process down, as will pumping the clutch pedal like a tart. If you have some finesse, you can do perfectly smooth, clutchless changes, even on a synchro 'box. The Volvo I-shift applies the engine brake as soon as a gear is disengaged, so it “arrives at” the correct speed for the next gear up more quickly.
Every post on this forum, relating to gearchanging on a constant mesh 'box, says not to use the clutch. It must have been a frustrating experience, sitting in the passenger seat of a vehicle when you were driving it.
I think you need to read what I said again and this time try to understand it.
Your first sentence actually describes what I said in the case of clutchless shifts.However if you want to de select the previous gear and put the thing into neutral without using the clutch you’ll need to lift off the accelerator in a way that allows the the load to be removed from the transmission which certainly isn’t a case of releasing the accelerator in the way that you can by declutching the transmission before shifting into neutral.If you just release the accelerator without declutching the transmission the load on the transmission won’t have time to decrease to zero it’ll just go straight from forward load over to overrun.For clutchless shifts it needs to be a slow,not full,lift to allow the forward loading to reduce to zero before deselecting the gear and shifting into neutral.
It would be interesting to sit in the passenger seat while you show me how to do perfectly smooth clutchless changes by just releasing the accelerator as you struggle to shift it into neutral between the time that the transmission loading changes from forward over to overrrun.Then you can sit there while I show you how to do the job properly and then how much faster the same process can be done using the clutch properly to make proper,by the book,double de clutched changes.Although somehow I doubt that you’d be able to understand the difference. 
Carryfast:
It would be interesting to sit in the passenger seat while you show me how to do perfectly smooth clutchless changes by just releasing the accelerator as you struggle to shift it into neutral between the time that the transmission loading changes from forward over to overrrun.
You apply a light load to the stick. It slips out with ease. I have done it in cars and lorries. On a car (synchro) 'box, I may dip the clutch pedal briefly, as I select the next gear. Why waste time wearing out the clutch and its actuation mechanism, if it is not necessary?
Carryfast:
Then you can sit there while I show you how to do the job properly and then how much faster the same process can be done using the clutch properly to make proper,by the book,double de clutched changes.Although somehow I doubt that you’d be able to understand the difference.
Have you ever driven a vehicle, of any type? There are quite a few experienced drivers on here, and you disagree with all of them, about everything, all of the time.
The genuine Foden clutch stop was ‘a real piece of work’. A totally different concept, the front of the layshaft was drilled for two pins ( which broke quite regularly). These engaged with two holes in the centre of a clutch disc, which was sandwiched between two externally splined discs. These splines mated with internal splines in the front of the layshaft cover. So it was vaguely like a motorbike clutch or more exactly like the top speed clutch in an automatic transmission. In front of these were two air diaphragms and the casing cover. So when the clutch was pressed right down and an air valve operated, the diaphragms expanded and slowed the layshaft… or not as the case might be.
Access to this fiddly assembly was through a small inspection plate in the bottom of the bellhousing, with just enough room to get one hand in, but not enough to see what you were doing. Not at all uncommon for a cooked clutch to melt the air pipe that operated the thing.
This thread has got a bit too heavy (technical) for me,I used to just change “up or down” with care,and never wore out a clutch or a gearbox ! But when “CF” comes on “spouting” a load of bollox the thread is obviously nearing the end of sensible discussion !! So I will freely admitt that there must have been,NO, have been numerous 8LXB engined Big J’s manufactured,so many in fact that they were thicker than flies on a cows arse at the height of British summer !!Cheers Bewick.
cav551:
The genuine Foden clutch stop was ‘a real piece of work’. A totally different concept, the front of the layshaft was drilled for two pins ( which broke quite regularly). These engaged with two holes in the centre of a clutch disc, which was sandwiched between two externally splined discs. These splines mated with internal splines in the front of the layshaft cover. So it was vaguely like a motorbike clutch or more exactly like the top speed clutch in an automatic transmission. In front of these were two air diaphragms and the casing cover. So when the clutch was pressed right down and an air valve operated, the diaphragms expanded and slowed the layshaft… or not as the case might be.Access to this fiddly assembly was through a small inspection plate in the bottom of the bellhousing, with just enough room to get one hand in, but not enough to see what you were doing. Not at all uncommon for a cooked clutch to melt the air pipe that operated the thing.
Yes, and when the pins broke the layshaft moved back and dropped down! Even when Loctited in they didn’t last long, the mainshaft nuts used to come lose as well and sieze the gearbox totally so we always kept a spare gearbox built up. Nowt to do with a Guy/ 8LXB I know, but at least the Foden existed…
Pete.