[zb]
anorak:
More good stuff from the man who necks a shot of EP90 before bedtime, and will last well into his eleventh decade as a result! 
Now- when did Mercedes start offering synchromesh? Was it available on those 1966 round-front tractors, which spearheaded Mercedesā first assault on the GB market?
I am working on the theory that the Swedish makes were more modern, technologically advanced that the others, and synchromesh was seen as a benefit. The vehicles were seen as more car-like to drive, and synchro was an obvious similarity. Previous lorries required more muscle and technique to drive, so anything that made the 1960s machines more like luxury cars was a marketing advantage, if nothing else. The driver of the day might prefer a dogbox in his rally car, but would rather rely on synchromesh at work.
If Merc et al were still offering constant mesh in the 1960s, that would make them less modern than Scania, therefore less attractive five or ten years down the line.
Ironically if youāre familiar with constant mesh to the point of far more use than the private car you usually just double de clutch/match the shifts instinctively anyway.
Which you still need to do to synchronise the clutch facings anyway regardless so might as well just match the gears as usual going through neutral too.
Which usually has the effect of doing the job of the synchros for them quicker and better and provides closer to the lighter shift quality of a constant mesh box.
In most cases the idea of synchros being more civilised is a myth, as opposed to an obstructive unecessary nuisance.
Donāt think thereās many car gearboxes where I wouldnāt rather remove the synchros given the option with the exception of old school Fords.
Carryfast:
[zb]
anorak:
More good stuff from the man who necks a shot of EP90 before bedtime, and will last well into his eleventh decade as a result!
Now- when did Mercedes start offering synchromesh? Was it available on those 1966 round-front tractors, which spearheaded Mercedesā first assault on the GB market?
I am working on the theory that the Swedish makes were more modern, technologically advanced that the others, and synchromesh was seen as a benefit. The vehicles were seen as more car-like to drive, and synchro was an obvious similarity. Previous lorries required more muscle and technique to drive, so anything that made the 1960s machines more like luxury cars was a marketing advantage, if nothing else. The driver of the day might prefer a dogbox in his rally car, but would rather rely on synchromesh at work.
If Merc et al were still offering constant mesh in the 1960s, that would make them less modern than Scania, therefore less attractive five or ten years down the line.
Ironically if youāre familiar with constant mesh to the point of far more use than the private car you usually just double de clutch/match the shifts instinctively anyway.
Which you still need to do to synchronise the clutch facings anyway regardless so might as well just match the gears as usual going through neutral too.
Which usually has the effect of doing the job of the synchros for them quicker and better and provides closer to the lighter shift quality of a constant mesh box.
In most cases the idea of synchros being more civilised is a myth, as opposed to an obstructive unecessary nuisance.
Donāt think thereās many car gearboxes where I wouldnāt rather remove the synchros given the option with the exception of old school Fords.
Mostly true but less clear cut than that 
. Firstly, I agree about car synchros: I too would personally sling mine. Getting back to lorries: itās true that drivers then all had constant-mesh experience and in any case you had to simulate it by pretending the synchro 'box was constant in order to pass the HGV test well into the '80s. But from then on we very quickly acquired a new workforce with no constant-mesh experience, which rapidly accelerated the demise of that kind of 'box. The nail in the coffin was the environmental sound pollution of the drive-by noise which scuppered the Road-Ranger in Euro-land.
The other problem was that some earlier synchro 'boxes didnāt take kindly to double de-clutching and contrary to what you say it didnāt do certain 'boxes any good. Thereās an article somewhere by Pat Kennett on this, quoting chapter and verse on why it damaged certain synchro 'boxes. Thereās another article somewhere showing that it does no damage to later synchro designs. Iāll try and dig them out and scan them. I do remember when being fed into the cab of a dreaded Scania 80 being told that under no circumstances must I double de-clutch because the clutch was operated by a cylinder that would stick if confused!! (I donāt know how true that is but it would be yet another nail in the coffin of that ill-fated model if it is!). As for the rest of your post: yes, and it is worth remembering that the best auto 'boxes today are constant-mesh. R
Just a rain-check to say that the gearbox issue appears to be a significant factor: CF and I havenāt hijacked the thread ! We might like to widen the discussion a bit though.
I have a list of Tractive units available to the UK during the period 1968, I wonāt type out the full list here but as probably expected the bigger end British makes were mostly CM boxes, the likes of Bedford, Ford, Commer, Dennis using 4/5 and 6 speed sync boxes. As for the foreigners the Mercedes LPS and LS 32 Ton units had 5 and 6 speed Sync apart from the LPS 1920/30, 1923/30 and LPS 2023/36 which had 6 speed CM boxes with an option of a 12 speed CM box. The Scania range LB 7630 to LBS 7646 used 10 speed Sync. The Volvo range F86 to FB88 used 8 Speed Sync. No Crash boxes at all in the list so if you think you drove something during the 60ās/70ās and thought it was a crash box then it wasnāt, the CM box often gets mistakenly called a crash box, there would have been crash on 1st gear for some CM boxes but that would be it. The list also includes engines; makes cylinders bhp torque, g/box; speeds type, axles; type and how many, wheelbasesā, tyres and a bit more. Magirus isnāt included. Franky.
ERF-NGC-European:
Mostly true but less clear cut than that . Firstly, I agree about car synchros: I too would personally sling mine. Getting back to lorries: itās true that drivers then all had constant-mesh experience and in any case you had to simulate it by pretending the synchro 'box was constant in order to pass the HGV test well into the '80s. But from then on we very quickly acquired a new workforce with no constant-mesh experience, which rapidly accelerated the demise of that kind of 'box. The nail in the coffin was the environmental sound pollution of the drive-by noise which scuppered the Road-Ranger in Euro-land.
The other problem was that some earlier synchro 'boxes didnāt take kindly to double de-clutching and contrary to what you say it didnāt do certain 'boxes any good. Thereās an article somewhere by Pat Kennett on this, quoting chapter and verse on why it damaged certain synchro 'boxes. Thereās another article somewhere showing that it does no damage to later synchro designs. Iāll try and dig them out and scan them. I do remember when being fed into the cab of a dreaded Scania 80 being told that under no circumstances must I double de-clutch because the clutch was operated by a cylinder that would stick if confused!! (I donāt know how true that is but it would be yet another nail in the coffin of that ill-fated model if it is!). As for the rest of your post: yes, and it is worth remembering that the best auto 'boxes today are constant-mesh. R
Firstly youāre right about the HGV test I was told exactly that for both of mine in 1980 and '85.
It would be interesting to see that article.I saw something similar some time ago on here written by a someone from one of the big transmission firms.I didnāt get it at all.
It went something along the lines of causing some sort of conflict among the meshing of the gear to be engaged when going through neutral on the mistaken premise that it was one operation.
When the shift into neutral and then back into the next gear after having synchronised input and output, are totally seperate distinct operations with no connection between any of them. 
As I saw/see itās just giving the synchros less work to do if any because thereās less or preferably no mismatch for them to deal with having been cancelled out during the shift through neutral.Nothing more nothing less than that.
If the shift loading when engaging the next gear up or down is then lighter and faster as a result that can only be the proof of that ?.
Bearing in mind if using the synchros itās then just shifted the same mismatch to the clutch facings instead, which still then needs to be cancelled out before re engaing the clutch anyway, it really is a solution to a non existent problem and just panders to bad driving habits as a result.
Thereās also no doubt that synchros just create more unecessary durability issues and are more expensive to overhaul when the time comes.Iāll go with no Fuller option was a liability in the case of the Swedes even into the 1980ās v the Fuller equipped opposition.
Frankydobo:
I have a list of Tractive units available to the UK during the period 1968, I wonāt type out the full list here but as probably expected the bigger end British makes were mostly CM boxes, the likes of Bedford, Ford, Commer, Dennis using 4/5 and 6 speed sync boxes. As for the foreigners the Mercedes LPS and LS 32 Ton units had 5 and 6 speed Sync apart from the LPS 1920/30, 1923/30 and LPS 2023/36 which had 6 speed CM boxes with an option of a 12 speed CM box. The Scania range LB 7630 to LBS 7646 used 10 speed Sync. The Volvo range F86 to FB88 used 8 Speed Sync. No Crash boxes at all in the list so if you think you drove something during the 60ās/70ās and thought it was a crash box then it wasnāt, the CM box often gets mistakenly called a crash box, there would have been crash on 1st gear for some CM boxes but that would be it. The list also includes engines; makes cylinders bhp torque, g/box; speeds type, axles; type and how many, wheelbasesā, tyres and a bit more. Magirus isnāt included. Franky.
Interesting list! And a useful reminder about crash boxes too - I think they belong to the '30s! Meanwhile, Iāve found one of the Pat Kennett articles and Iāll hunt out the others. Iāve scanned below (read bottom one first!):
ERF-NGC-European:
Just a rain-check to say that the gearbox issue appears to be a significant factor: .
To the point where I think Fuller conversions on Volvos and Scanias havenāt been unheard of ?.That would be the smoking gun. 
Frankydobo:
if you think you drove something during the 60ās/70ās and thought it was a crash box then it wasnāt, the CM box often gets mistakenly called a crash box, there would have been crash on 1st gear for some CM boxes but that would be it.
+1 Sliding Mesh of the actual gear train as opposed to constant mesh of the gear train engaged by dogs.Both synchronised the same way but donāt think anyone would be brave enough to try clutchless shifts of the former.
ERF-NGC-European:
Iāve found one of the Pat Kennett articles and Iāll hunt out the others. Iāve scanned below (read bottom one first!):
Thanks Robert.I still donāt get it.
Either way up or down all that a double de clutched shift is doing is at worse lessening and at best removing the mismatch that the synchros have to deal with.A relatively mismatched double de clutched shift is still less load on the synchros than no matching at all.
What does he mean by allowing a ājerkā on a downshift by not matching the engine speed to synchronise the clutch facings.
That isnāt helping engine braking thatās just putting a massive shock loading through the clutch and driveline when the clutch is re engaged against the idling engine.
As for making sure that the clutch is disengaged when shifting into neutral thatās exactly the correct issue that contradicts floated/clutchless shifts in the case of a CM box.
IE without the clutch being disengaged itās unlikely that the transmission will be in a totally unloaded state, itāll either be under load or overrun, as the the gear hub/dog is taken out of mesh.
Frankydobo:
I have a list of Tractive units available to the UK during the period 1968, I wonāt type out the full list here but as probably expected the bigger end British makes were mostly CM boxes, the likes of Bedford, Ford, Commer, Dennis using 4/5 and 6 speed sync boxes. As for the foreigners the Mercedes LPS and LS 32 Ton units had 5 and 6 speed Sync apart from the LPS 1920/30, 1923/30 and LPS 2023/36 which had 6 speed CM boxes with an option of a 12 speed CM box. The Scania range LB 7630 to LBS 7646 used 10 speed Sync. The Volvo range F86 to FB88 used 8 Speed Sync. No Crash boxes at all in the list so if you think you drove something during the 60ās/70ās and thought it was a crash box then it wasnāt, the CM box often gets mistakenly called a crash box, there would have been crash on 1st gear for some CM boxes but that would be it. The list also includes engines; makes cylinders bhp torque, g/box; speeds type, axles; type and how many, wheelbasesā, tyres and a bit more. Magirus isnāt included. Franky.
I did not know the '20 and '23 Mercedes models were available in GB, just the later 1418 and 1924. I have never heard of one being bought by a GB haulier. If those latter models had synchro, it blows my earlier theory out of the water- Merc and Scania were almost perfectly matched, spec for spec.
Does anyone have sales figures for tractor units in the period 1960 to 1980?
ERF-NGC-European:
According to my records, Carryfast is right 
. Like CF Iām a bit of a gearbox obsessive when it comes to lorries - and proud of it. I used to drive Series 2 Scanias with the R cab, all of which had the range-change 10sp box. I also drove several P-cabbed 112s (P112M) artics, all of which had the 10-sp splitter version. Most of these were rental /lease units.
Over 30 years ago i drove a few P cabbed Scanias one of which had a peculiar splitter arrangement IIRC , the first 3 shifts worked like any other splitter with each gear splitting up and down whereas the last 2 worked differently. 1 2 and 3 like i said each having half gears then into 4th low then move the lever into 5th low then back down again with the split moved to high then back into 5th with the switch in high . It took a little getting used to
Yes I remember that too Ramone, I did have a demo P112 6x2 for a week so it could possibly have been on that, canāt recall any other make I drove that had the same system, I did think it performed well while I had it and I believe it didnāt have the awkward 6 High change movement our R112ās had which we often missed out apart from certain conditions. Franky.
Thanks for that bit from Pat K Rob, such memories from his better driving columns, were like a bible to me at the time, excellent font of wisdom and knowledge.
Carryfast:
ERF-NGC-European:
Iāve found one of the Pat Kennett articles and Iāll hunt out the others. Iāve scanned below (read bottom one first!):
Thanks Robert.I still donāt get it.
Either way up or down all that a double de clutched shift is doing is at worse lessening and at best removing the mismatch that the synchros have to deal with.A relatively mismatched double de clutched shift is still less load on the synchros than no matching at all.
What does he mean by allowing a ājerkā on a downshift by not matching the engine speed to synchronise the clutch facings.
That isnāt helping engine braking thatās just putting a massive shock loading through the clutch and driveline when the clutch is re engaged against the idling engine.
As for making sure that the clutch is disengaged when shifting into neutral thatās exactly the correct issue that contradicts floated/clutchless shifts in the case of a CM box.
IE without the clutch being disengaged itās unlikely that the transmission will be in a totally unloaded state, itāll either be under load or overrun, as the the gear hub/dog is taken out of mesh.
Iām sort of with you on this; but I donāt think itās a black-or-white issue. What Pat seems to be saying is that itās fine to use the old double de-clutch technique with synchro boxes as long as you execute the changes sensitively. Iāve come across this similar nuance in his other writings on the subject. Going back to what we were saying about the old HGV test where you were expected to replicate these techniques with a synchro 'box to demonstrate ability to do the job; people forget that one of the essential elements of the test in those days was the ability to demonstrate a sense of attunedness to the mechanics of the engine / transmission / clutch / switchgear etc of the vehicle you were in charge of. A good driver should be able to get the best out of whatever lorry he is given.
ERF-NGC-European:
A good driver should be able to get the best out of whatever lorry he is given.
+1
On that note I donāt think Iāve ever driven anything in which a double de clutched shift didnāt actually improve the speed and quality of synchro box shifts up or down.From Bedford TJ to Merc 2534.DAF 2300 ATI , 85 and 95 16 speeds all being a better starting point though.
As for Volvo and Scania I donāt think there can be any doubt that Fuller conversions were carried out on them for reasons of superior driveability and durability and overall operating costs which speaks for itself. 
> ERF-NGC-European:
> Whisperingās Merc sounds interesting and was probably properly maintained and successful, especially if it was on M/E work. However, '70s air-assisted anything to do with gearboxes was, in my experience, usually disasterous if you had so much as an air-leak, a dodgy compressor or youād used up all your air manoevering or you were in heavy traffic - all commonplace in those days. Air-operated splitter-switches and range-change switches were always the first to be denied air, so if youād used a fair bit of air braking, the chances were that you may struggle to change down and with a non-synchro box they were slim. Electrically operated switches were better. Air-operated wipers were a disaster for the same reason.
The V10 Merc was well geared up to provide air for both the gearbox & clutch and being on ME work service brakes were used sparingly.
BUT you had to carry a drum of fine gauge air pipe in case of splits in one of the lines, which would soon bring you to a halt.
Behind the front panel there was an array of vertical pipes and it was a few seconds job to identify the faulty piping and slip a new length on, however, fortunately it was a rare occurence.
The 1932 sounds like a superb flagship vehicle. Mercedes should have promoted it as such in GB, like Scania did with the 140. I donāt think Mercedesā cause was helped when they changed to the NG- it looked more like a competitor for the Ford D series than the Scania 111. Lagging a bit behind in the bhp race did not help.
Frankydobo:
Yes I remember that too Ramone, I did have a demo P112 6x2 for a week so it could possibly have been on that, canāt recall any other make I drove that had the same system, I did think it performed well while I had it and I believe it didnāt have the awkward 6 High change movement our R112ās had which we often missed out apart from certain conditions. Franky.
Thank god for that Franky , for a moment i thought iād dreamt it. It was A599 KLJ a 4 x 2 and it was a good motor
> [zb]
> anorak:
> The 1932 sounds like a superb flagship vehicle. Mercedes should have promoted it as such in GB, like Scania did with the 140. I donāt think Mercedesā cause was helped when they changed to the NG- it looked more like a competitor for the Ford D series than the Scania 111. Lagging a bit behind in the bhp race did not help.
Agree totally, the big cab LPS was superb for lengthy trips and at 6ā2" I found it easy to walk about and could stand up fully when the roof hatch was open.
For some reason Mercedes seemed to treat the UK as a Truck Backwater and sold vehicles that were in competition with 180/190 powered British motors, albeit with an unbreakable build quality & better cabs.
I saw a few short LPS cabbed Irish wagons, but it was a very difficult to get MB UK to supply anything above the poverty UK spec until the NG came along and that to my mind was a retrograde step.
To be fair to Mercedes there are probably 000ās of NGs still earning their keep across the world, so maybe not such a bad move.
[zb]
anorak:
The 1932 sounds like a superb flagship vehicle. Mercedes should have promoted it as such in GB.Lagging a bit behind in the bhp race did not help.
V10 rigid late 1970s and just about the first proper heavy truck I ever ādroveā and before Iād got my HGV licence after Iād sorted out how to get the thing started if only between the factory and the yard for some outside work.Some D series.
flickr.com/photos/pobox448/4 ā¦ otostream/
