Lift axles

[carryfast]

bobthedog:
You really have no idea, do you…

Obviously yes I do when all the different criterea of total drive axle weights,grip co efficients,and forces are factored into the equation.

[newmercman]

Welcome back wire, now Mark I must’ve misunderstood you earlier when you were saying that you thought you may get stuck on that hill, then I’m pretty sure snow chains were mentioned, then a detour to avoid said hill eight…nine…ten…TKO

I know, it’s solid ice, but I thought with all your difflocks and that you’d be able to climb Everest

All your drag coeffients and enertia and other gobblledegook do not mean anything Crazyfast, the fact is if an axle or pair of axles are lightly loaded then it/they are just going to spin away uselessly, by having a lift you can increase the weight on the driven axle of a 6x2 and gain enough traction to get going

Now back to wire, yes I know about the 20000lb limit on a single axle, but we’re talking about getting up a hill or out of a junction, not running 700 miles down the road, anyone who was silly enough to do that would be in the same institution as your new mate Crazyfast, you don’t run all day with your diff and crosslocks engaged do you So effectively your truck is a single drive on any given day, if you hit a big patch of ice at the bottom of a hill you’re going to flick your switches…and spin all eight tyres, in a 6x2 however, you hit the switch and that pushes the wheels left on the ground into the ice so that it’s much harder for them to spin

Even if I’m wrong and the 6x4 is better, I would rather have a 6x2, even in the terrible conditions we get here, how many times are you at risk of getting stuck? Not many, but all day, every day, those extra mechanical components are eating up fuel, just as I said at the start, Trev has tried to explain this point too

[wheel_nut]

If the roads are as slaipe as they look on Bobs pictures and grip is such an issue, wtf would you want more engine braking? Electronic retarders, Jacobs brakes and other systems have switches to turn them off, just like the tag or lift axles have switches to lift them or dump the air. But you would never turn them all off in every scenario, unless like Marc NMM, he was turning off the TC for fun

You can have as many formulas as you like, co efficients and force factors, but when you start to lose grip at the crest of a hill, lifting an undriven axle momentarily will generally get you over the top, without fuss or drama. Is the main objection of using lift axles solely because you are scared of the VOSA popping out from behind a frosty Elm tree with a FP in hand?

I presume in your special engineering design studio with the soft wallcoverings, you will have a valid reason why multi leaf springs are far better than single air bellows!

[newmercman]

Malc, now we have two of them at it, this could drag on like a 6x4 trying to get up an icy hill, I wonder if Luke will buy dinner for the 1000th poster on here too

[carryfast]

Wheel Nut:
If the roads are as slaipe as they look on Bobs pictures and grip is such an issue, wtf would you want more engine braking?

The fact is a fully freighted artic will fry it’s brakes going down a zb great long down grade in zb weather just the same as in the summer.So why bother with fitting a jake or whatever type of engine braking magnification equipment if you want to turn the thing off right at the time when you most need it. And under btd’s logic newmercman would also throw the back brakes away on his beast as well as turning off the T/C because in most situations the front wheels are loaded up to around twice as much under braking as the rears.I might try the same idea on the Jag too but if it locks it’s front wheels up and wipes out Fritz’s Trabant trying to slow nearly 2 tonnes down from 160 mph on the autobahn I’ll just tell the law that it seemed like a good idea at the time when I factored in the extra weight on the front wheels under braking at that speed. But in this case we’re throwing even more braking effort away because on a double drive bogie the weights on both drive axles are about equal.

[phil_the_book]

---

Carryfast:

Wheel Nut:
If the roads are as slaipe as they look on Bobs pictures and grip is such an issue, wtf would you want more engine braking?

-The fact is a fully freighted artic will fry it’s brakes going down a zb great long down grade in zb weather just the same as in the summer.So why bother with fitting a jake or whatever type of engine braking magnification equipment if you want to turn the thing off right at the time when you most need it. And under btd’s logic newmercman would also throw the back brakes away on his beast as well as turning off the T/C because in most situations the front wheels are loaded up to around twice as much under braking as the rears.I might try the same idea on the Jag too but if it locks it’s front wheels up and wipes out Fritz’s Trabant trying to slow nearly 2 tonnes down from 160 mph on the autobahn I’ll just tell the law that it seemed like a good idea at the time when I factored in the extra weight on the front wheels under braking at that speed. But in this case we’re throwing even more braking effort away because on a double drive bogie the weights on both drive axles are about equal.

I know i should not do this but i think you are wrong in bad weather ie rain or snow there is quite a marked difference in brake fade any water coming in contact with disc or shoe will minimise fade not completely but will certainly slow the glazing which is the main contribution to fade thats the reason why racing trucks have water cooled brake systems.I have come down a few long drags and always preffered it in the wet.

[switchlogic]

Carryfast:

Wheel Nut:
If the roads are as slaipe as they look on Bobs pictures and grip is such an issue, wtf would you want more engine braking?

The fact is a fully freighted artic will fry it’s brakes going down a zb great long down grade in zb weather just the same as in the summer.So why bother with fitting a jake or whatever type of engine braking magnification equipment if you want to turn the thing off right at the time when you most need it. And under btd’s logic newmercman would also throw the back brakes away on his beast as well as turning off the T/C because in most situations the front wheels are loaded up to around twice as much under braking as the rears.I might try the same idea on the Jag too but if it locks it’s front wheels up and wipes out Fritz’s Trabant trying to slow nearly 2 tonnes down from 160 mph on the autobahn I’ll just tell the law that it seemed like a good idea at the time when I factored in the extra weight on the front wheels under braking at that speed. But in this case we’re throwing even more braking effort away because on a double drive bogie the weights on both drive axles are about equal.

This is where you could be showing your out of date! It takes a really startling amount of braking in a modern truck to bring on brake fade. As for the retarder, our Scanias are fitted with them, they’re great, very powerful, I can set the speed I want it to come down hills and also have it come on with the brakes, but, when the weather gets really bad it’s the first switch I push to turn off. If you want to come down a steep Icy hill on a powerful retarder your a braver man than me. In my first hand experience they can be lethal in such situations.

My final point, say for instance you got your way and the whole of Europe was runiing on 6x4’s, how much sooner do you think the oil will run out, with hundreds of thousands more trucks doing a half to one mile per gallon less? Let’s not get bogged down in climate change as I know many of you don’t believe it but the oil IS going run out, it’s a fact, and if 6x2’s and 4x2’s mean it happens later then that’s good enough reason for me.

P.s, I’m not going to commit myself to another lunch, who knows who I’d have to buy it for!

[tockwith_training]

How long is this thread! Well impressed. In my FH13 it says in the handbook not to worry about the VEB in snow because it’s linked with the abs sensors and will disable it’s self if it notices the drive wheels turning slower than the undriven wheels. Not sure how well it works, waiting for a bit more snow. I think most modern trucks cut off the exhauster when the drive wheels begin to slip, sure on the old ones like pre 2000 it may cause you to be looking the wrong way down a slippy road.

[carryfast]

switchlogic:

Carryfast:

Wheel Nut:
If the roads are as slaipe as they look on Bobs pictures and grip is such an issue, wtf would you want more engine braking?

The fact is a fully freighted artic will fry it’s brakes going down a zb great long down grade in zb weather just the same as in the summer.So why bother with fitting a jake or whatever type of engine braking magnification equipment if you want to turn the thing off right at the time when you most need it. And under btd’s logic newmercman would also throw the back brakes away on his beast as well as turning off the T/C because in most situations the front wheels are loaded up to around twice as much under braking as the rears.I might try the same idea on the Jag too but if it locks it’s front wheels up and wipes out Fritz’s Trabant trying to slow nearly 2 tonnes down from 160 mph on the autobahn I’ll just tell the law that it seemed like a good idea at the time when I factored in the extra weight on the front wheels under braking at that speed. But in this case we’re throwing even more braking effort away because on a double drive bogie the weights on both drive axles are about equal.

This is where you could be showing your out of date! It takes a really startling amount of braking in a modern truck to bring on brake fade. As for the retarder, our Scanias are fitted with them, they’re great, very powerful, I can set the speed I want it to come down hills and also have it come on with the brakes, but, when the weather gets really bad it’s the first switch I push to turn off. If you want to come down a steep Icy hill on a powerful retarder your a braver man than me. In my first hand experience they can be lethal in such situations.

My final point, say for instance you got your way and the whole of Europe was runiing on 6x4’s, how much sooner do you think the oil will run out, with hundreds of thousands more trucks doing a half to one mile per gallon less? Let’s not get bogged down in climate change as I know many of you don’t believe it but the oil IS going run out, it’s a fact, and if 6x2’s and 4x2’s mean it happens later then that’s good enough reason for me.

P.s, I’m not going to commit myself to another lunch, who knows who I’d have to buy it for!

I think your statement,about a powerful retarder being lethal in bad conditions,just confirms what wire was trying to say concerning jake brakes (which are also powerful) if used with euro type single drive axles.But the oil running out bs just confirms the euro bs views of how to run a truck properly versus the North American one.

[carryfast]

Tockwith Training:
How long is this thread! Well impressed. In my FH13 it says in the handbook not to worry about the VEB in snow because it’s linked with the abs sensors and will disable it’s self if it notices the drive wheels turning slower than the undriven wheels. Not sure how well it works, waiting for a bit more snow. I think most modern trucks cut off the exhauster when the drive wheels begin to slip, sure on the old ones like pre 2000 it may cause you to be looking the wrong way down a slippy road.

So the answer to wire’s question would be throw away one of the two drive axles and replace it with an undriven one,transfer some of the weight which it would have carried and put that on the one he’s got left,and when the single drive axle loses grip with the jake brake on (because it’s now trying to put the same amount of force onto the road with half as many driving wheels) just turn it off. As for the opposite problem of traction when he’s reached the bottom of the hill and needs to start climbing again we’ll cross that bridge when we come to it.

[switchlogic]

Oh wow Carryfast, you’ve surpassed yourself! I didn’t bring up climate change because this isn’t the time or place for a long debate but I really didn’t think I’d ever meet someone who denies the oil is running out! Are you some mad genius who’s found an infinite supply of oil under his living room? I admire your perseverance in this argument but I’m gonna give up on this post now as your really are a complete loon!

Just out of interest, for someone who is so obviously obsessed with the inferior technology in North America why don’t you live there? You strike me as someone who say a lot and does little.

[carryfast]

switchlogic:
Oh wow Carryfast, you’ve surpassed yourself! I didn’t bring up climate change because this isn’t the time or place for a long debate but I really didn’t think I’d ever meet someone who denies the oil is running out! Are you some mad genius who’s found an infinite supply of oil under his living room? I admire your perseverance in this argument but I’m gonna give up on this post now as your really are a complete loon!

Just out of interest, for someone who is so obviously obsessed with the inferior technology in North America why don’t you live there? You strike me as someone who say a lot and does little.

It’s lucky that they did’nt believe that the oil is running out at Airbus either when they decided to fit that zb great big plane of theirs with four engines instead of just two when one of those engines blew up the other day while it was climbing and that did’nt seem to be thought of when they built Terminal 4 at Heathrow to take all the extra plane passengers based on the future growth in air transport all based on tax free fuel. But I was thinking of emigrating to North America but when I wanted to go they would’nt let Brits in,probably because they thought that all Brits are raving green nutters , and it’s too late now.But it would have been a lot easier if I’d have been born a yank instead of a Brit.

[phil_the_book]

Carryfast:

switchlogic:
Oh wow Carryfast, you’ve surpassed yourself! I didn’t bring up climate change because this isn’t the time or place for a long debate but I really didn’t think I’d ever meet someone who denies the oil is running out! Are you some mad genius who’s found an infinite supply of oil under his living room? I admire your perseverance in this argument but I’m gonna give up on this post now as your really are a complete loon!

Just out of interest, for someone who is so obviously obsessed with the inferior technology in North America why don’t you live there? You strike me as someone who say a lot and does little.

It’s lucky that they did’nt believe that the oil is running out at Airbus either when they decided to fit that zb great big plane of theirs with four engines instead of just two when one of those engines blew up the other day while it was climbing and that did’nt seem to be thought of when they built Terminal 4 at Heathrow to take all the extra plane passengers based on the future growth in air transport all based on tax free fuel. But I was thinking of emigrating to North America but when I wanted to go they would’nt let Brits in,probably because they thought that all Brits are raving green nutters , and it’s too late now.But it would have been a lot easier if I’d have been born a yank instead of a Brit.

It would have been better for all of us if you had been born a Martain.

[carryfast]

phil the book:

Carryfast:

switchlogic:
Oh wow Carryfast, you’ve surpassed yourself! I didn’t bring up climate change because this isn’t the time or place for a long debate but I really didn’t think I’d ever meet someone who denies the oil is running out! Are you some mad genius who’s found an infinite supply of oil under his living room? I admire your perseverance in this argument but I’m gonna give up on this post now as your really are a complete loon!

Just out of interest, for someone who is so obviously obsessed with the inferior technology in North America why don’t you live there? You strike me as someone who say a lot and does little.

It’s lucky that they did’nt believe that the oil is running out at Airbus either when they decided to fit that zb great big plane of theirs with four engines instead of just two when one of those engines blew up the other day while it was climbing and that did’nt seem to be thought of when they built Terminal 4 at Heathrow to take all the extra plane passengers based on the future growth in air transport all based on tax free fuel. But I was thinking of emigrating to North America but when I wanted to go they would’nt let Brits in,probably because they thought that all Brits are raving green nutters , and it’s too late now.But it would have been a lot easier if I’d have been born a yank instead of a Brit.

It would have been better for all of us if you had been born a Martain.

But the yanks decided that four wheel drive was still better even on the moon where the gravity is even less than on Mars when they built the Lunar rover .

[wire]

Welcome back wire, now Mark I must’ve misunderstood you earlier when you were saying that you thought you may get stuck on that hill, then I’m pretty sure snow chains were mentioned, then a detour to avoid said hill eight…nine…ten…TKO

I hear you Mark but to be fair it actually touched on -32 degc last night according to the dashboard. If i had gone the way we were talking about i would have been chaining up regardless of axle configuration i am sure.
I love my Pete 379 as you know and i don’t reckon i would want it modifying it into some kind of 6x2 Euro hybrid. Why, i would rather see a pair those crappy cissy mirrors bolted to the hood before i would let that happen, Lol.

[carryfast]

wire:

Welcome back wire, now Mark I must’ve misunderstood you earlier when you were saying that you thought you may get stuck on that hill, then I’m pretty sure snow chains were mentioned, then a detour to avoid said hill eight…nine…ten…TKO

I hear you Mark but to be fair it actually touched on -32 degc last night according to the dashboard. If i had gone the way we were talking about i would have been chaining up regardless of axle configuration i am sure.
I love my Pete 379 as you know and i don’t reckon i would want it modifying it into some kind of 6x2 Euro hybrid. Why, i would rather see a pair those crappy cissy mirrors bolted to the hood before i would let that happen, Lol.

The scary thing is that there are nutters around who see 6x4 tractor units as ‘inferior American technology’ and who would probably refuse to drive one until the workshops have taken a gas axe to one of the drive axles and fitted it with a lifting tag or a mid lift instead.

[newmercman]

Carryfast:

phil the book:

Carryfast:

switchlogic:
Oh wow Carryfast, you’ve surpassed yourself! I didn’t bring up climate change because this isn’t the time or place for a long debate but I really didn’t think I’d ever meet someone who denies the oil is running out! Are you some mad genius who’s found an infinite supply of oil under his living room? I admire your perseverance in this argument but I’m gonna give up on this post now as your really are a complete loon!

Just out of interest, for someone who is so obviously obsessed with the inferior technology in North America why don’t you live there? You strike me as someone who say a lot and does little.

It’s lucky that they did’nt believe that the oil is running out at Airbus either when they decided to fit that zb great big plane of theirs with four engines instead of just two when one of those engines blew up the other day while it was climbing and that did’nt seem to be thought of when they built Terminal 4 at Heathrow to take all the extra plane passengers based on the future growth in air transport all based on tax free fuel. But I was thinking of emigrating to North America but when I wanted to go they would’nt let Brits in,probably because they thought that all Brits are raving green nutters , and it’s too late now.But it would have been a lot easier if I’d have been born a yank instead of a Brit.

It would have been better for all of us if you had been born a Martain.

But the yanks decided that four wheel drive was still better even on the moon where the gravity is even less than on Mars when they built the Lunar rover .

This gets my vote as the best response on this whole thread, PMSL

[bobthedog]

Carryfast:
The fact is a fully freighted artic will fry it’s brakes going down a zb great long down grade in zb weather just the same as in the summer.So why bother with fitting a jake or whatever type of engine braking magnification equipment if you want to turn the thing off right at the time when you most need it. And under btd’s logic newmercman would also throw the back brakes away on his beast as well as turning off the T/C because in most situations the front wheels are loaded up to around twice as much under braking as the rears.I might try the same idea on the Jag too but if it locks it’s front wheels up and wipes out Fritz’s Trabant trying to slow nearly 2 tonnes down from 160 mph on the autobahn I’ll just tell the law that it seemed like a good idea at the time when I factored in the extra weight on the front wheels under braking at that speed. But in this case we’re throwing even more braking effort away because on a double drive bogie the weights on both drive axles are about equal.

Erm, hang on a minute… Why have you dragged me into this one?

Now, regarding your point about the weight on the front axle… Well actually, you are wrong yet again. See, these units are long enough that the weight on the steers is fairly constant at 12000 lbs or so. We don’t tend to get the same problems as euro spec trucks because we use short necked trailers and they are a long way behind the steers.

As to your continued protestations that more than one wheel is driving at any given time, we do not have 1983 2.8 injection LS diffs, we have heavy Rockwells. So your BS about coefficients is just that… BS. I have 13.5 tonnes on the front and 13.2 on the trailer bogie. My steers are showing 5.2 tonnes/ So if we follow your theory about even weight distribution, then each one of my drive wheels has a mere 3.4 tonnes bearing on it. With that in mind, and considering that the power divider is little more than a diff, I only ever have 3.4 tonnes being driven. With a single drive axle, I would have considerably more, would’t I? If the one axle is loaded to a max of 10.5tonnes then I would have 5.25 tonnes being driven… Pure mathematics.

[newmercman]

We all have our points of view on this, my view comes from previous experience of owning my own trucks and paying the bills, with this in mind I would spec a 6x2 midlift, I would do it for one reason…CASH A single drive will suffer parasitic energy loss of around 7%, which is almost half of the amount lost by a double drive set up, that saves fuel, as the energy loss is just wasted power and power comes from fuel, which I have to spend CASH to get. Secondly I could run trailer tyres on the lifting axle, they have a much lower rolling resistance than drive pattern tyres, so I burn less fuel going down the road and save more CASH. I could also run my steer tyres right out on this axle after they’re too worn for the front and save even more CASH, an added benefit would be using the lift axle in tight turns and when pulling away, this could add more mileage to my drive tyres, saving me CASH. I would also lose 800lbs or so and moving less weight means I use less diesel, meaning I save more CASH. Lower maintenance from running one diff and less stress on bushes etc from the lack or torsion when manouvering with the wheels up mean my costs go down and save me CASH, can you see a pattern emerging

Now from a traction standpoint, I’m currently parked up four hours down the road from my planned stop for the night, the reason, the roads are like an ice rink, my traction control light was like a strobe light and that was just driving down the road in a straight line, the slightest push on the loud pedal made the wheels spin, I had my power divider in so I had four tyres spinning away, with diff locks on (if I had them) all I would’ve gained was another four spinning tyres, even if I had my mid lift money maker, I would still be parked up, the only way that it would be safe out there tonight is in a tracked vehicle and preferably one that was armour plated too, that Crazyfreak is what we encounter here, it’s either ok to drive, or it’s time to park it up, there’s no middle ground, no matter how many wheels go round when you step on the gas

[bobthedog]

Nope, Mark. You have to keep rolling. Better for these nasty diesel guzzlers to be rolling when the motor is running.

That said, I have just wasted boatloads of time on here and am going to get rolling for an hour I think.