Volvo B10BLE (CNG)
-
I suggest that you have to view things from a macro view.Originally posted by Scania N113CRB luver:Yea! Mercs are the best! Ofcuz larh! Super good suspension, no or little rattling, unlike Volvo B7RLEs, which rattles like a rattelsnake. Scania cannot say, cause old bus and technology, O405 quite old liao, BUT STILL NO RATTLING MAN!, pure german quality! Volvo B7RLEs are new yet already rattle.
And pls dont say ZF sux and Voith is the best. Both got good points and bad points, you said ZF suc maybe because you pointed out some "black horses", for example the LO3x, which suffered from prob in gear changing. Voiths i agree is the best, I love Voiths on the VO2x and Habits!!! They rock!!
But VO2x got BIG problem. If the bus was on a hill , the gearbox tends to refuse to downshift, all the way its top gear. And sometimes the BC didn't put in full trottle (sekali is already full trottle), all this makes VO2x worst hill climbers. Last time took one of it and the bus was so FREAKING FREAKING slow, like those ah ma ah pek got serious leg and back prob, walk super slow.
ZF is wastage of gears, but excellent in climbing hills, due to multiple speeds, but they SUCK in top speed , acceleration is the best. Gearboxx also sound very nice, the "wheeoooorrrr sound" Voith can hear the whistle sound only when stopping, which can be hard to hear when u are at a bus stop. If you lucky a Voith-ed bus stop near the bus stop, you can hear it. ZF very distinctive, can hear when the bus leaves the bus stop, without fail.
In terms of technical superiority & make quality, Voith is better than ZF in many ways. It's difficult for me to go into details if you do not understand the concept of how the gearbox works.
The ZF however despite costs also substantially being technically & make inferior to Voith also proves statistically to lose out to Voith breaking down ratios & the need to replace them is more in terms of percentage. And it is a lot more. Exact details I cannot reveal in the public forum.
When you say Voiths are poor hill climbers that's not true. ZF has a gear ratio of 3.43(1st), 2.01(2nd), 1.42(3rd), 1(4th, direct coupling), 4.84(Reverse) for 4HP. But Voith has a whoppping 6.1(1st), 1.43(2nd), 1(direct coupling), 5.2(reverse) for a 3 gear Voith 3N models 4 gear voiths have 6.1(1st), 1.43(2nd), 1.00(3rd, direct coupling), 0.73(4th), 5.2(reverse) for 4 gears Voith 3N models.
In terms of top speed, Voith are better. In terms of up hill, Voith has a powerful first gear twice the power of ZF. If you mount it into the same engine you will know the difference. Although ZF has a more flater ratio, It does not give kinda boost needed to move the capacity of passengers when needed compared to Voith.
Also those wheeoooorrrr sounds are not gearboxes. Because if gearboxes make those sounds then the gearbox must be in such a terrible condition that I have not even heard of before. NOrmally those constantly meshing sounds are from the axle or diff unit. BEcause in the gearboxes, gears are constantly meshed. Only the locking of different clutches decide which gear to use. Study the sun and planetary gear system. This will be the gearbox concept that's going to dominate the future market.
I am currently waiting for my car to be brought into SGP from France by Sime Darby Autofrance awaiting the launch of the Peugeot 207. The gearbox itself is tiptronic. Very hardly will you find the traditional manual meshing gearbox unless it's a very basic model. In buses however, I don't think it is financially sensible to manufacture buses with manual gearboxes anymore. Because unlikely it can sell well anymore.
The BC I meet do not have any preferences to which gearbox. As long as can be driven easily, don't breakdown, hopefully got air con. OK already.
And Yes!! MB0405 is legendary. Easy to maintain and more BC prefer MB0405. Easy to drive too. I have asked so many BC before when they are at my workshop while I give them a bus to cameo, like the most recent, one BL shuttle service BC need to take bus from me during a weekend, I asked him Volvo MK4 or MB0405. And guess his choice?
100% of them prefers MB0405. -
wowo y so many ppl chat or paste abut the watever thing.........?
-
Icic! Yea! Voith is more "technologically advanced" read about the technical stuffs at Voith website. But you forgot to mention that Voith tends to refuse to downshift. Try taking a VO2x when it goes uphill, the gearbox doesn't downshift, but instead at the top/second gear. You said that Voiths have excellent and powerful first gear, but what if its engaged in the top/second gear and the bus engine lacks power (like the VSO) and the bus is going uphill? Definitely a ZF-ed bus will overtake it.Originally posted by MS:I suggest that you have to view things from a macro view.
In terms of technical superiority & make quality, Voith is better than ZF in many ways. It's difficult for me to go into details if you do not understand the concept of how the gearbox works.
The ZF however despite costs also substantially being technically & make inferior to Voith also proves statistically to lose out to Voith breaking down ratios & the need to replace them is more in terms of percentage. And it is a lot more. Exact details I cannot reveal in the public forum.
When you say Voiths are poor hill climbers that's not true. ZF has a gear ratio of 3.43(1st), 2.01(2nd), 1.42(3rd), 1(4th, direct coupling), 4.84(Reverse) for 4HP. But Voith has a whoppping 6.1(1st), 1.43(2nd), 1(direct coupling), 5.2(reverse) for a 3 gear Voith 3N models 4 gear voiths have 6.1(1st), 1.43(2nd), 1.00(3rd, direct coupling), 0.73(4th), 5.2(reverse) for 4 gears Voith 3N models.
In terms of top speed, Voith are better. In terms of up hill, Voith has a powerful first gear twice the power of ZF. If you mount it into the same engine you will know the difference. Although ZF has a more flater ratio, It does not give kinda boost needed to move the capacity of passengers when needed compared to Voith.
Also those wheeoooorrrr sounds are not gearboxes. Because if gearboxes make those sounds then the gearbox must be in such a terrible condition that I have not even heard of before. NOrmally those constantly meshing sounds are from the axle or diff unit. BEcause in the gearboxes, gears are constantly meshed. Only the locking of different clutches decide which gear to use. Study the sun and planetary gear system. This will be the gearbox concept that's going to dominate the future market.
I am currently waiting for my car to be brought into SGP from France by Sime Darby Autofrance awaiting the launch of the Peugeot 207. The gearbox itself is tiptronic. Very hardly will you find the traditional manual meshing gearbox unless it's a very basic model. In buses however, I don't think it is financially sensible to manufacture buses with manual gearboxes anymore. Because unlikely it can sell well anymore.
The BC I meet do not have any preferences to which gearbox. As long as can be driven easily, don't breakdown, hopefully got air con. OK already.
And Yes!! MB0405 is legendary. Easy to maintain and more BC prefer MB0405. Easy to drive too. I have asked so many BC before when they are at my workshop while I give them a bus to cameo, like the most recent, one BL shuttle service BC need to take bus from me during a weekend, I asked him Volvo MK4 or MB0405. And guess his choice?
100% of them prefers MB0405.
Aiya, lets stop arguing / debating . I prefer ZFs and you prefer Voiths. That's enough.
But thanks for the technical info btw! Appreciate it alot. Actually, the VSO caused me to have a bad impression of Voiths. Voith made VSO a SUPER slow runner. VSO are better off with ZFs. But i start to prefer Voiths now, especially the VO2x (my fav voith bus) and Habits(only those in the category TIB1208U---TIB1247G and Volgren bendies(TIB1188T-TIB1197S). I love the VO2x the most! Sounds abit like VSO. -
Yea, Volvo B10M abit like pig, very slow. Or lyk difficult to drive.Originally posted by MS:And Yes!! MB0405 is legendary. Easy to maintain and more BC prefer MB0405. Easy to drive too. I have asked so many BC before when they are at my workshop while I give them a bus to cameo, like the most recent, one BL shuttle service BC need to take bus from me during a weekend, I asked him Volvo MK4 or MB0405. And guess his choice?
100% of them prefers MB0405.
MB O405 like very responsive like that. Both SBST and SMRT ones looks like very easy to drive. Next time maybe i become BC, then must drive MB O405! My favourite also!
Any bus fans would like to be BC when they grow up? Only for a short while ofcuz, say 2-3 years. I wanna get a taste of living with a bus everyday. -
You urself dun spout nonsense online. Someone here has better technical knowledge in you and hence don't try to act like as if you know things well for ZF and Voith transmission.Originally posted by Scania N113CRB luver:Yea! Mercs are the best! Ofcuz larh! Super good suspension, no or little rattling, unlike Volvo B7RLEs, which rattles like a rattelsnake. Scania cannot say, cause old bus and technology, O405 quite old liao, BUT STILL NO RATTLING MAN!, pure german quality! Volvo B7RLEs are new yet already rattle.
And pls dont say ZF sux and Voith is the best. Both got good points and bad points, you said ZF suc maybe because you pointed out some "black horses", for example the LO3x, which suffered from prob in gear changing. Voiths i agree is the best, I love Voiths on the VO2x and Habits!!! They rock!!
But VO2x got BIG problem. If the bus was on a hill , the gearbox tends to refuse to downshift, all the way its top gear. And sometimes the BC didn't put in full trottle (sekali is already full trottle), all this makes VO2x worst hill climbers. Last time took one of it and the bus was so FREAKING FREAKING slow, like those ah ma ah pek got serious leg and back prob, walk super slow.
ZF is wastage of gears, but excellent in climbing hills, due to multiple speeds, but they SUCK in top speed , acceleration is the best. Gearboxx also sound very nice, the "wheeoooorrrr sound" Voith can hear the whistle sound only when stopping, which can be hard to hear when u are at a bus stop. If you lucky a Voith-ed bus stop near the bus stop, you can hear it. ZF very distinctive, can hear when the bus leaves the bus stop, without fail.
Seriously speaking, please don't show off when you have NOTHING at all. -
- edited -
-
wa act seh...Originally posted by SBS9816E:You urself dun spout nonsense online. Someone here has better technical knowledge in you and hence don't try to act like as if you know things well for ZF and Voith transmission.
Seriously speaking, please don't show off when you have NOTHING at all.
-
That's because B10Ms are not truly citybuses as it had high profile tyres and our dear SBST loves to tightened the speed ranging from 55-65km/h thus making the acceleration slow like shit.MBs/Lances used low profile tyres so the acceleration a bit powerful,N113CRB because of the SAAB-Scania technology while VSO is because of the speed limiter.Originally posted by Scania N113CRB luver:Yea, Volvo B10M abit like pig, very slow. Or lyk difficult to drive.
MB O405 like very responsive like that. Both SBST and SMRT ones looks like very easy to drive. Next time maybe i become BC, then must drive MB O405! My favourite also!
Any bus fans would like to be BC when they grow up? Only for a short while ofcuz, say 2-3 years. I wanna get a taste of living with a bus everyday. -
Hihi! I think I need to explain because you're misleading the other readers. Basically what you're saying in the first part is all wrong.Originally posted by Scania N113CRB luver:Icic! Yea! Voith is more "technologically advanced" read about the technical stuffs at Voith website. But you forgot to mention that Voith tends to refuse to downshift. Try taking a VO2x when it goes uphill, the gearbox doesn't downshift, but instead at the top/second gear. You said that Voiths have excellent and powerful first gear, but what if its engaged in the top/second gear and the bus engine lacks power (like the VSO) and the bus is going uphill? Definitely a ZF-ed bus will overtake it.
Aiya, lets stop arguing / debating . I prefer ZFs and you prefer Voiths. That's enough. But thanks for the technical info btw! Appreciate it alot. Actually, the VSO caused me to have a bad impression of Voiths. Voith made VSO a SUPER slow runner. VSO are better off with ZFs. But i start to prefer Voiths now, especially the VO2x (my fav voith bus) and Habits(only those in the category TIB1208U---TIB1247G and Volgren bendies(TIB1188T-TIB1197S). I love the VO2x the most! Sounds abit like VSO.
Correction to your myth on gearbox
The gearboxes are not designed to 'tend to refuse to downshift'. When the gearbox refuse to downshift, to us the technical personnel means that the gearbox solenoid is faulty or the gearbox clutch is unable to lock the correct gear when the input shaft decreases.
Statistically shows that only few cases involving Voiths compared to the loads of ZF with such problems. what you encountered is unfortunately a case by case one time experience. And not the entire macro situation. That is why I initially suggested to you that you should view things from a macro view. Like this you're reacting by jumping into info which is a great taboo in leadership. Only paparazzis or gossiping housewives use this way of making conclusions.
Even when the bus comes into the workshop no one is going to buy the story the BC says 'unable to change gear' totally. We still need to screen the case with the assistance of the ZF mobidig for ZF gearboxes and Voith gearbox tester for Voith. From there, we will know exactly which solenoid is not working. Also we need to check the ATF colour to determine whether the clutch inside are worn.
As you said when the bus with Voith gearbox cannot downshift then the ZF gearbox bus will be able to overtake it. It's true. But again you're looking at things from a stereotyped view. I have said: Voith have much lesser problems than ZF. If you're to look at statistics, you'll actually find Voith over taking ZF up the slope many more times than the ZF overtaking the Voith.
The use of a gearbox
The gearbox do not generate it's own rotary power. It taps the rotary power from the engine. So the engine itself plays an important role to determine which bus is more powerful and faster. The gearbox merely capitalise on the limited effects of engine rotary power and convert it into a variety of speed via torque.
Voith is technically better than ZF because:
(1) Voith are able to adjust the clutch back pressure to accomodate the wear of the clutch so as to maximise the use of the clutch which leads to longer lifespan. ZF is unable to.
(2) Voith gearbox solenoids are installed externally. ZF are installed internally which means it is exposed to the hot ATF running all over the solenoid & harness valve body assembly. And if the seal at the harness is worn after some time, ATF can leak in and short the pins inside which causes the gearbox to engage clutches abnormally. so sometimes the BC can drive half way and suddenly the gearbox disengage gear for the BC. Or downshift for the BC. Worst case scenarios whereby the gearbox will attempt to engage reverse gear while on the move. But reverse gear can only be engage when the vehicle is stationery. So it will rather cause unwanted wear on the clutches. All these problems Voith do not have. When gears are unable to engage for Voith simply mean that the solenoid is damaged and a replacement can be done in a jiffy without getting hands dirty or scalded by the hot ATF like ZF.
(3) Voith spare parts are well made compared to ZF. The main cable of the gearbox which connects the gearbox to the ECU is a very critical component. The outer layer of the ZF cable is made up of cheap plastic braided coverings that are not waterproof. Voith is made up of solid insulation to fend against wear and heat.
There are many other points which will have to employ the use of pictures and some are sensitive info which I will not reveal.
Understanding of matters
Of course you have the right to support the brand you like and I have to respect that. But I have to right the wrongs with proper facts and you need to admit that facts are still facts. Even if you don't like the better gearbox, doesn't mean that gearbox is inferior to the one you support.
I hope this insight can help you to learn ways of understanding things effectively. -
You take 179 VO2x and LO3x when climbing the hill and you see for yourself. Both types will usually reach 2nd gear, but most of the time, the BC will downshift to the first gear.Originally posted by Scania N113CRB luver:But you forgot to mention that Voith tends to refuse to downshift.
But on a VO2x empty bus, usually, the bus can maintain 2nd gear all the way up the hill.
-
Interesting... How about MK2s? Do BCs like MK2s? (both CAC & NAC)Originally posted by MS:shuttle service BC need to take bus from me during a weekend, I asked him Volvo MK4 or MB0405. And guess his choice?
100% of them prefers MB0405. -
Norman can answer your question.Originally posted by stooper:Interesting... How about MK2s? Do BCs like MK2s? (both CAC & NAC)
But what I find is that if with a choice, most BC ask me for air con buses. A handful will say any bus will do.
Between double decks and single decks, more will opt for single decks if given a choice. If not I will assign double decks as much as possible unless the BC not authorised to drive. Can be checked on the spot with a special program to know which licence the BC holds.
But the most popular is MB0405. I never think about least popular because the MB0405 really overshadows the rest. -
O.405 are also preferred in the east side as well. BCs from amdep/brbp preferred O.405 as the steering is light. From what I heard during IMF period, hgdep BCs got the chance to drive O.405 and they really like it.
-
What have you contributed compared to MS and Norman? Did you just barge in, make comments about people and run?Originally posted by SBS9816E:You urself dun spout nonsense online. Someone here has better technical knowledge in you and hence don't try to act like as if you know things well for ZF and Voith transmission.
Seriously speaking, please don't show off when you have NOTHING at all. -
Got the experience driving O405s when driving S82/100/158 last time and can tell you 1 thing,Best!My 2nd fav is MKIV Strider cause most of it have a good acceleration followed by OAC Scania,reasons?Most of the buses had this aircon blower temp adjustment which is still in operational mode unlike CAC where the roof was leaking like crazy when raining!It's a good choice that CRB using Voith,Suitable with its Turbocharged engine.MKII is a good runner but the suspension is really a let down.The last one should be MKIV DM3500 but only a few is good i can say.Overall i hear from most BCs the preferred choice goes to MB O405s & Striders for SDs,Tridents/B9TLs and sorry Winston Leylands,Though the steering is the minus factor.Originally posted by MS:Norman can answer your question.
But what I find is that if with a choice, most BC ask me for air con buses. A handful will say any bus will do.
Between double decks and single decks, more will opt for single decks if given a choice. If not I will assign double decks as much as possible unless the BC not authorised to drive. Can be checked on the spot with a special program to know which licence the BC holds.
But the most popular is MB0405. I never think about least popular because the MB0405 really overshadows the rest. -
Alright, just to share my knowledge.
Voith DIWA transmissions are designed very differently to ZF-Ecomat transmissions. Especially of interest is the design of the torque converter.
The Voith transmission (at least on paper) seems to have a lower first gear ratio compared to the ZF (5.05:1 for a Voith D864.3), however, because of the design of the Voith torque converter, this is the ratio for the entire 1st gear because the Voith does not have seperate unlocked and lock-up stages. In contrast, the first gear ratio given by ZF for their Ecomat transmissions is 3.43:1, but this ratio is achieved during the "lock-up" stage - in the hydraulic stage, that ratio is lowered to nearly 6:1, giving impressive initial transmission power. This is why you will experience better initial acceleration with a ZF transmission.
In practice, buses with Voith transmissions generally have lower final drive ratios to compensate for the (lack of) acceleration. ZF transmissions can use a slightly higher final drive ratio yet achieve the same acceleration as the Voith, while achieving the same top-end speed (comparing a Voith D864.3 and ZF 5HP 500). The new 6-speed ZF transmissions give a whole new meaning to the word "flexibility" - 0.59:1 in 6th gear means that an extremely low final drive can be used, providing outstanding acceleration AND top speed while improving economy. To prove my point, compare the performance betwen a Mercedes-Benz O 405 with a Voith and then a ZF.
And talking about economy, the ZF transmission has more intermediate gears, meaning that there is always a correct gear for each situation. Compare that with the Voith that easily pushes engine revs on new buses to near 2000 rpm and you will be able to see a visible difference. What the ZF transmission lacks in durability it more than makes up in fuel efficiency and engine protection.
Regards,
Dave -
He's contributed far more than you ever have, Alan.Originally posted by ^tamago^:What have you contributed compared to MS and Norman? Did you just barge in, make comments about people and run? -
hi dave... wrong infos.Originally posted by Powered_By_CNG:Alright, just to share my knowledge.
Voith DIWA transmissions are designed very differently to ZF-Ecomat transmissions. Especially of interest is the design of the torque converter.
The Voith transmission (at least on paper) seems to have a lower first gear ratio compared to the ZF (5.05:1 for a Voith D864.3), however, because of the design of the Voith torque converter, this is the ratio for the entire 1st gear because the Voith does not have seperate unlocked and lock-up stages. In contrast, the first gear ratio given by ZF for their Ecomat transmissions is 3.43:1, but this ratio is achieved during the "lock-up" stage - in the hydraulic stage, that ratio is lowered to nearly 6:1, giving impressive initial transmission power. This is why you will experience better initial acceleration with a ZF transmission.
In practice, buses with Voith transmissions generally have lower final drive ratios to compensate for the (lack of) acceleration. ZF transmissions can use a slightly higher final drive ratio yet achieve the same acceleration as the Voith, while achieving the same top-end speed (comparing a Voith D864.3 and ZF 5HP 500). The new 6-speed ZF transmissions give a whole new meaning to the word "flexibility" - 0.59:1 in 6th gear means that an extremely low final drive can be used, providing outstanding acceleration AND top speed while improving economy. To prove my point, compare the performance betwen a Mercedes-Benz O 405 with a Voith and then a ZF.
And talking about economy, the ZF transmission has more intermediate gears, meaning that there is always a correct gear for each situation. Compare that with the Voith that easily pushes engine revs on new buses to near 2000 rpm and you will be able to see a visible difference. What the ZF transmission lacks in durability it more than makes up in fuel efficiency and engine protection.
Regards,
Dave
Gear Ratios
Gear ratio is the ratio between n revolutions made by the driven gear is to the n revolutions made by drive gear.
eg. Gear Ratio for Voith is 6.1 for 1st gear, Gear ratio for ZF is 3.43 for 1st gear
Meaning that for every revolution the driven gear makes in the Voith gearbox for first gear, the driven gear makes 6.1 revolutions.
For every revolution the driven gear makes in the ZF gearbox for 1st gear, the drive gear rotates 3.43 revolutions.
The bigger the gear ratio the more powerful and slower it is.
However the lower the gear ratio the faster the bus will be. Therefore anything lower than 1 is an even more deeper exploitation of the engine power to bring about greater speeds.
Let me illustrate:
If I have a higher gear ratio, the bus moves towards a concrete wall and try to ram the wall down. The bus will not ram it down via impact. But via slow unstoppable strength. It will only give up until the bus cracks or the wall collasps.
But if the gear ratio is low, the bus initially builds up speed with a lower gear until a desired speed to accomodate the lower gear ratio but higher speed, the bus is trying to bring down the wall via impact. But if that impact fails & the bus is still intact, for the bus to try a second time is impossible because it will need to start from 1st gear and build up the speed again until it reaches a higher gear with lower gear ratio.
Torque converter
only comes in use in first gear. Torque converter helps to multiply the torque in order to help to start move the heavy bus.
Lock Up
will only come after the torque converter seizes to work when 2nd gear comes in. In order to cancel the powerful torque and start moving with lesser torque but more speed.
Gearbox brains
The gearbox has 2 'brains'. One is the ECU while the other is the valve body run by solenoids which receives signal from the ECU to decide which clutch to lock.
ZF 4HP
A B C D E F solenoids
H solenoid is the lock up.
Reverse gear = C + F
Neutral = no solenoid activated
1st gear = A + F (no H because under the influence of torque converter)
2nd gear = A + E + H
3rd gear = A + D + H
4th gear = A + B + H
In other words, if solenoid 'A' is not working, the bus can only reverse gear. Or if the pins and connections between the ECU to the solenoid 'A' is short or open, the bus can only reverse gear. And don't laugh. It happened before and the bus was at 4th floor. So have a guess how did we get the bus to the first floor workshop? It was a Leyland 3 axle superbus.
For Voith I need to use a lot of pictures to explain as the Voith gearbox is more complicated with different brake stages and retarders being catered for in Voith gearbox.
However, up till now I have never needed to activate the whole workshop to push any Voith gearbox buses before while I've already pushed many Leylands already. And damn... if the engine is not working, we cannot build up the air to release the brakes then we'll be in deep shit. The superior designs of the Voith gearboxes helps to extend the lifespan of the gearbox which led to lower maintenance costs on Voith Transmission. I designed the repair kit for both the ZF and Voith gearboxes for use in workshop that's why I am so sure that Voith gearboxes have a cheaper package yet longer lasting lifespan due to it's design. I have the Tansmission Technology modular training notes. If you're interested I can lend out for photocopy. It's not any confidential info also. Known by many people in this industry.
Oops... did I accidentally reveal the answer on how I got the Leyland down from 4th floor? -
Is this a CNG thread or a gears thread?Originally posted by MS:hi dave... wrong infos.
Gear Ratios
Gear ratio is the ratio between n revolutions made by the driven gear is to the n revolutions made by drive gear.
eg. Gear Ratio for Voith is 6.1 for 1st gear, Gear ratio for ZF is 3.43 for 1st gear
Meaning that for every revolution the driven gear makes in the Voith gearbox for first gear, the driven gear makes 6.1 revolutions.
For every revolution the driven gear makes in the ZF gearbox for 1st gear, the drive gear rotates 3.43 revolutions.
The bigger the gear ratio the more powerful and slower it is.
However the lower the gear ratio the faster the bus will be. Therefore anything lower than 1 is an even more deeper exploitation of the engine power to bring about greater speeds.
Let me illustrate:
If I have a higher gear ratio, the bus moves towards a concrete wall and try to ram the wall down. The bus will not ram it down via impact. But via slow unstoppable strength. It will only give up until the bus cracks or the wall collasps.
But if the gear ratio is low, the bus initially builds up speed with a lower gear until a desired speed to accomodate the lower gear ratio but higher speed, the bus is trying to bring down the wall via impact. But if that impact fails & the bus is still intact, for the bus to try a second time is impossible because it will need to start from 1st gear and build up the speed again until it reaches a higher gear with lower gear ratio.
Torque converter
only comes in use in first gear. Torque converter helps to multiply the torque in order to help to start move the heavy bus.
Lock Up
will only come after the torque converter seizes to work when 2nd gear comes in. In order to cancel the powerful torque and start moving with lesser torque but more speed.
Gearbox brains
The gearbox has 2 'brains'. One is the ECU while the other is the valve body run by solenoids which receives signal from the ECU to decide which clutch to lock.
ZF 4HP
A B C D E F solenoids
H solenoid is the lock up.
Reverse gear = C + F
Neutral = no solenoid activated
1st gear = A + F (no H because under the influence of torque converter)
2nd gear = A + E + H
3rd gear = A + D + H
4th gear = A + B + H
In other words, if solenoid 'A' is not working, the bus can only reverse gear. Or if the pins and connections between the ECU to the solenoid 'A' is short or open, the bus can only reverse gear. And don't laugh. It happened before and the bus was at 4th floor. So have a guess how did we get the bus to the first floor workshop? It was a Leyland 3 axle superbus.
For Voith I need to use a lot of pictures to explain as the Voith gearbox is more complicated with different brake stages and retarders being catered for in Voith gearbox.
However, up till now I have never needed to activate the whole workshop to push any Voith gearbox buses before while I've already pushed many Leylands already. And damn... if the engine is not working, we cannot build up the air to release the brakes then we'll be in deep shit. The superior designs of the Voith gearboxes helps to extend the lifespan of the gearbox which led to lower maintenance costs on Voith Transmission. I designed the repair kit for both the ZF and Voith gearboxes for use in workshop that's why I am so sure that Voith gearboxes have a cheaper package yet longer lasting lifespan due to it's design. I have the Tansmission Technology modular training notes. If you're interested I can lend out for photocopy. It's not any confidential info also. Known by many people in this industry.
Oops... did I accidentally reveal the answer on how I got the Leyland down from 4th floor? -
Originally posted by MS:
No you didn't reveal it.
hi dave... wrong infos.
[b]Gear Ratios
Gear ratio is the ratio between n revolutions made by the driven gear is to the n revolutions made by drive gear.
eg. Gear Ratio for Voith is 6.1 for 1st gear, Gear ratio for ZF is 3.43 for 1st gear
Meaning that for every revolution the driven gear makes in the Voith gearbox for first gear, the driven gear makes 6.1 revolutions.
For every revolution the driven gear makes in the ZF gearbox for 1st gear, the drive gear rotates 3.43 revolutions.
The bigger the gear ratio the more powerful and slower it is.
However the lower the gear ratio the faster the bus will be. Therefore anything lower than 1 is an even more deeper exploitation of the engine power to bring about greater speeds.
Let me illustrate:
If I have a higher gear ratio, the bus moves towards a concrete wall and try to ram the wall down. The bus will not ram it down via impact. But via slow unstoppable strength. It will only give up until the bus cracks or the wall collasps.
But if the gear ratio is low, the bus initially builds up speed with a lower gear until a desired speed to accomodate the lower gear ratio but higher speed, the bus is trying to bring down the wall via impact. But if that impact fails & the bus is still intact, for the bus to try a second time is impossible because it will need to start from 1st gear and build up the speed again until it reaches a higher gear with lower gear ratio.
Torque converter
only comes in use in first gear. Torque converter helps to multiply the torque in order to help to start move the heavy bus.
Lock Up
will only come after the torque converter seizes to work when 2nd gear comes in. In order to cancel the powerful torque and start moving with lesser torque but more speed.
Gearbox brains
The gearbox has 2 'brains'. One is the ECU while the other is the valve body run by solenoids which receives signal from the ECU to decide which clutch to lock.
ZF 4HP
A B C D E F solenoids
H solenoid is the lock up.
Reverse gear = C + F
Neutral = no solenoid activated
1st gear = A + F (no H because under the influence of torque converter)
2nd gear = A + E + H
3rd gear = A + D + H
4th gear = A + B + H
In other words, if solenoid 'A' is not working, the bus can only reverse gear. Or if the pins and connections between the ECU to the solenoid 'A' is short or open, the bus can only reverse gear. And don't laugh. It happened before and the bus was at 4th floor. So have a guess how did we get the bus to the first floor workshop? It was a Leyland 3 axle superbus.
For Voith I need to use a lot of pictures to explain as the Voith gearbox is more complicated with different brake stages and retarders being catered for in Voith gearbox.
However, up till now I have never needed to activate the whole workshop to push any Voith gearbox buses before while I've already pushed many Leylands already. And damn... if the engine is not working, we cannot build up the air to release the brakes then we'll be in deep shit. The superior designs of the Voith gearboxes helps to extend the lifespan of the gearbox which led to lower maintenance costs on Voith Transmission. I designed the repair kit for both the ZF and Voith gearboxes for use in workshop that's why I am so sure that Voith gearboxes have a cheaper package yet longer lasting lifespan due to it's design. I have the Tansmission Technology modular training notes. If you're interested I can lend out for photocopy. It's not any confidential info also. Known by many people in this industry.
Oops... did I accidentally reveal the answer on how I got the Leyland down from 4th floor?[/b] But u hint it larh......
Btw i agree with dave. ZF allows better fuel efficiency and engine protection. Cause diesel engines actually weren't designed for high rpm working jobs( what i meant high rpm is reacher near the max engine rpm), which explains why ships and diesel generation uses lower rpm diesel engines. Maybe im wrong about this, i dont know, i dont wish to start a debate again.
But dont worry about ZF faults. ZF is coming up with the new ZF Ecolife series. Hopefully the new gearbox doesn't have the solenoid design bugs. Yea, i stongly agree with what MS said, if solenoid A is spoilt, the bus can only move in reverse. This is extremely troublesome (imagine moving a DD in reverse down a 4 storey building like what MS has said. OPPS! I revealed the ans.
).
Actually, i still prefer ZF. Remember about what dave said about engine protection, about engine being runned at high rpm near its max working range? If Voith makes engine overhauling more frequent due to more engine strains, now you have to cover more engine costs as well. But if driving a bus in reverse because the solenoid is spoilt and the bus cnt move in forward gears and that damages the engine even more, i have nth else more to say.
And also, dave also mentioned that due to ZF having correct gears for each situation, the engine will have less strains and thus engine breakdowns will be less frequent, just like riding a 18-speed MTB and a 24-speed MTB. Obviously the one with the 24-speed will go up the hill much more easily than the 18-speed, and you wont get tired that easily as well.
btw why is it that Voith-ed Habits have that "roaring" sound when speeding? ZF-ed Habits dont have leh.
Ok larh, stop arguing and debate whos right and who's not. We both have our interest in certain things and we have to respect that. No point arguing and end up getting unhappy with each other. So lets peace and stop here ok?
Ok larhs, we like heck care bout TS question liao. Talk about CNG bus become gearbox debation. -
Although this info in off topic. I do not mind as its a very INFOMATIVE Post instead of those +1s.Originally posted by SBS9806J:Is this a CNG thread or a gears thread?
(This post can be in fact also be called +1).
so +1 -
+1Originally posted by SBS1985C:Although this info in off topic. I do not mind as its a very INFOMATIVE Post instead of those +1s.
(This post can be in fact also be called +1).
so +1 -
@MS: A "lock-up" torque converter is in fact a hydraulic clutch that links the bus engine with the transmission input shaft. Also, lower (higher number) final drive ratio gives more responsive acceleration but less top speed, and a higher (lower number) final drive ratio gives less responsive acceleration but more top speed. Same applies for gear ratios for transmissions because both ratios are directly linked.
Alright, back to my specialty now, CNG-powered bus engines. Singapore has only experimented with one type of CNG engine and that is the Volvo GH10B with open-loop lean-burn combustion and central gas injection via four injection valves. Such a system provides adequate performance but suffers greatly if there is too much variation in fuel quality. The latest CNG engines offer either closed-loop stoichiometric or closed-loop lean-burn combustion and provides resistance to such variations, and are also able to adjust the air/fuel mixture in real-time to allow for such things as temperature and pressure changes, ignition condition, and other manufacturing tolerances. The new generation also provides signifcantly improved power and torque outputs as well as improved responsiveness. The latest Volvo CNG engine is the G9A which features a maximum rating of 300 PS/1400 Nm, closed-loop stoichiometric combustion with exhaust gas recirculation and a three-way catalytic converter to meet Euro 5+/EEV emissions specifications.
Regards,
Dave -
... ...
Initially there was also a thread in businfohub which led into gearbox. I have previously indicated that there're many wrong infos about gearbox being spreaded around. That is why I initiated explanations.
But if you all insisted on your own theories I have nothing else to say.
I have the official SBST transmission module theory textbook my explanations are taken from the textbook and hands on training. Also on the ground 1st hand experience.
But if you still feel that it is not enough to convince that some of your theories are actually very wrong. I have explained once and that's quite sufficient. Then I have no choice. No pt arguing further also. -
eh... no. it's pushed down manually. its too dangerous to reverse drive down.Originally posted by Scania N113CRB luver:No you didn't reveal it. But u hint it larh......
Btw i agree with dave. ZF allows better fuel efficiency and engine protection. Cause diesel engines actually weren't designed for high rpm working jobs( what i meant high rpm is reacher near the max engine rpm), which explains why ships and diesel generation uses lower rpm diesel engines. Maybe im wrong about this, i dont know, i dont wish to start a debate again.
But dont worry about ZF faults. ZF is coming up with the new ZF Ecolife series. Hopefully the new gearbox doesn't have the solenoid design bugs. Yea, i stongly agree with what MS said, if solenoid A is spoilt, the bus can only move in reverse. This is extremely troublesome (imagine moving a DD in reverse down a 4 storey building like what MS has said. OPPS! I revealed the ans. ).
Actually, i still prefer ZF. Remember about what dave said about engine protection, about engine being runned at high rpm near its max working range? If Voith makes engine overhauling more frequent due to more engine strains, now you have to cover more engine costs as well. But if driving a bus in reverse because the solenoid is spoilt and the bus cnt move in forward gears and that damages the engine even more, i have nth else more to say.
And also, dave also mentioned that due to ZF having correct gears for each situation, the engine will have less strains and thus engine breakdowns will be less frequent, just like riding a 18-speed MTB and a 24-speed MTB. Obviously the one with the 24-speed will go up the hill much more easily than the 18-speed, and you wont get tired that easily as well.
btw why is it that Voith-ed Habits have that "roaring" sound when speeding? ZF-ed Habits dont have leh.
Ok larh, stop arguing and debate whos right and who's not. We both have our interest in certain things and we have to respect that. No point arguing and end up getting unhappy with each other. So lets peace and stop here ok?
Ok larhs, we like heck care bout TS question liao. Talk about CNG bus become gearbox debation.