Boggie lift.

[stina]

Hej!

I have a refection, if this is the wrong Place, let me know and I will be silent.

Almost every truck at Your side of the water has tandem traction, often without diff lock.

Almost every truck in Sweden and North Europé wher it´s Winter condition has singel axle traction and a good boggie lift and diff lock.

I Think if I am behind one of Yours going uphill and You have to stop for put on chains, If I have the tires we use in Winter time I am sure it´s possible to stop and start in the same hill with the boggie lifted and diffs locked.

It´s even harder to understand for the trucks wich is used in the South wher never is snow.

My I have an explanation?

Stina.

[TeamsterGrrrl]

Part of it is bad experience with dead axles that didn't lift back in the 50s and 60s, causing truckers to demand tandem drive on everything. Part of it is the warranty situation- buy a single drive tractor and convert it yourself to a lift axle tandem, and the manufacturer may deny warranty coverage for any failure of the frame, rear suspension, and drive axle. Their are also issues with making the ABS work with a DIY lift axle. The air lift pusher axle Volvo and Mack brands are offering looks like it should work, but I suspect forcing the buyer to take it in a package along with their AMT will hold down market share.

[david wild]

Now for the real answer, North American drivers just have not been smart enough to operate them, if it is not stupid proof than it just will not fly, those of us who driven in Europe and other destination understand how they work and are fine with them, now they have been tried and those that have learned to use them love them, in fact at the local KW dealer there are new trucks on the lot set up that way. back in the 70s and 80s Winn Dixie ran a punch of single axle trucks equipped with a belt that drove the rear axle, Salyer ran a KW with pusher set up, that would have been in the early 80s, been a bunch Canadian trucks that have had them for years and yes they do go better in the snow if you know how to operate them. so they have been around but you need qualified drivers and we have a lack of those.

I wish we could get MAN trucks imported here but the pajama wearing flip flop hero steering wheel holders here would be lost in a real truck and if it does not have a snout no one will drive them, been told it's a penis thing or lack of.

[Quickfarms]

After seeing some of these steering wheel holders in action you will understand.

A lot of trucks do have lockers in them.

[stina]

Of course ther must be a stronger frame for to handle a boggie lift. The ABS/EBS system handle the lift without any problem also the suspension and banjo, we have the same banjo and air spring either it´s 4X2 or 6X2.

I read about it some time ago and I understand some brand in US sell trucks with "my koncept" today, if I understand it right the solution was to connect the third axles air spring to the EBS system. When the traction Wheel slips the system dump air from the third axle suspension, but dont lift the axle. This solution will never be succesful!

If You wait until You loose the traction it´s to late, and the axle must be lifted.

Before we reach an icy uphill the diff is locked and the boggielift is activated, if the truck is Heavy loaded it may not lift the axle but it just touch the ground, and we have 17.000-20.000 kg on the traction Wheel. Most of the time it´s succses.

I have lots of 6X2 pusher tractors thru the year, some brand have steering pusher, some dont but all is liftable wich it must be.

Pusher is a very good solution in most cases, but if we have a truck wich is working in a mountain area fex Norway the Classic 6X2 with boggielift is a better solution. We don´t get the same pressure on the traction Wheels with the pusher.

The pusher solution is never used on the big trucks with box.

I send a Pictures of some "box trucks", those is DAF, an Dutch brand and sister to Peterbilt and Kenworth. I have lots of them and it´s ok. Those ar 460/480 HP, 64.000 kg and single traction axle.

Stina.

[stina]

What´s "AMT"?

Stina.

[TeamsterGrrrl]

Automated Manual Transmission. In North America Volvo and Mack brands are offering lift pusher axle 6 by 2 tractors, but only in a package with the AMT.

[Vladislav]

Do you really mean 6x2 configuration works better on an icy uphill with 3rd axle up in relation to 6x4 with 2 drive axles interlocked?

I'm not much in truck driving but surprize hearing that.

[stina]

Ok! We have I-shift on Volvo and AS-Tronic in DAF wich use ZF gearboxes.

I am sure that the 6X2 solution is best in most situations, if the truck is very Heavy loaded I don´t Think the different is very big but when it´s empty or light loaded the different is dramatic. I also Think we use Moore aggresive pattern on the tires, in combination with the high axle pressure with lifted boggie it´s possible to climb steep icy uphills mostly without any problem.

That´s also why the Classic 6X2 is better than a 6X2 pusher. When You lift the third axle the weight moves from ther to the traction axle, also some weight from the front axle is mooving to the traction. That gives some around 20.000 kg on the traction axle.

When You lift the pusher, most of the weight goes to the traction, but some goes to the steering axle. That give something around 15.000 kg to the traction. It makes big different.

Stina.

[david wild]

see no snout

[stina]

We use the space for Cargo! We have "snout" on some special trucks, but mostly on toys!

Stina.

[Timmyb]

I have heard of liftable axles getting caught up while off road.

Would a bogie, with interaxle diff lock (front and back) and cross locks (left and right) work just as good?

[stina]

If You work on soft dirt roads or building places I Think the tandem traction is a good choise. The only kind of trucks wher it´s common with tandem in Sweden is logging trucks, but even ther is used different system to unload the rear axle to get a better turning area.

Wheelbase on our trucks is between 4,2-4,8 meter for a 6X2, we measure the wheelbas from front to traction axle.

I Think we need some less space for to handle the vehicle.

Stina.

[mrsmackpaul]

lazy axels arent very common in Australia all suspension must be load sharing and I believe (but could be wrong) that back in the days of lazy axles and the load sharing requirement too many trucks would get stuck in driveways as lifting axles werent allowed because the load sharing part of the rules wouldnt have applied and since those days in the 70's they have never really caught on a few got sold but not many maybe 1 in 50 or 1 in 100 trucks at the most

Paul

[stina]

My Picture of Australia is a lot of dirt roads wich Went very bad and slippry when it´s raining, that must be the perfect conditions for tandem.

Stina.

[mrsmackpaul]

My Picture of Australia is a lot of dirt roads wich Went very bad and slippry when it´s raining, that must be the perfect conditions for tandem.

Stina.

we have a few dirt roads all main highways are sealed bitumen Australia is very flat with a long way between towns once you 150km in from the east coast 100's of km between towns

But Australia has a bigger area of snow then Switzerland !!! a fact I only recently learnt

Paul

[stina]

I know ther is ski resorts in South east corner but I dont know how big the area is. Is it common with snow in low terrain in Winter time or is it just on the hills?

I also thought ther was a lot of dirt roads in the area of mining and farming. Is that incorrect? I have also been told that the roads North from Brisbane is very rough, I know Volvo make some transmission test ther of that reason.

I found Jake Brake parts to one of my Volvos in Brisbane of that reason.

Stina.