Explain to the dunce please - lifting axles.

Explain to the dunce please - lifting axles.

Author
Discussion

thismonkeyhere

Original Poster:

10,731 posts

238 months

Monday 11th March 2013
quotequote all
As in the second axle on a three axle tractor unit, first axle on a three axle trailer etc, that lift when the vehicle is, presumably, unladen.

I've not given it a great deal of thought, tbh, but I always assumed that it was to reduce tyre wear, but then I thought - surely it just increases tyre wear on those still in contact with the road. So maybe it results in a fuel saving due to lower resistance? Maybe a bit of both, maybe a different reason by brain hasn't yet thought of?

So what's the 'official' purpose of them?

Cyberprog

2,232 posts

190 months

Monday 11th March 2013
quotequote all
A lift axle is usually there to raise the amount of weight that can be carried by the tractor unit. They are then able to lift up to reduce drag/wear when the unit is unloaded.

s p a c e m a n

11,002 posts

155 months

Monday 11th March 2013
quotequote all
Because we like toys biggrin

Lifting the axle also gives more grip on the drive wheels.

ZR1cliff

17,999 posts

256 months

Monday 11th March 2013
quotequote all
The lift axle is only a type of assister for, if i'm right, an extra 4 tons. Because it's a single wheel per side and doesn't really do much I'm sure it helps with saving tyre wear without a detrimental effect to tyre wear to the others when empty and stowed.

Also found that when empty and the axle is 'up' there is better economy.

iva cosworth

44,044 posts

170 months

Monday 11th March 2013
quotequote all
I think it also decreases "unsprung weight" to carry rather than drag it about.

That's the scientific answer possiblynerd

The 6 wheeler we have also has the option of dropping it and switching it on to give

4WD if the other axle loses traction on uneven ground.

pja

270 posts

232 months

Monday 11th March 2013
quotequote all
As has been said, it saves on tyre wear, brake wear, fuel when unladen
Also I think there is or used to be a road tax saving as well??

Iva cosworth
I've never seen a lift drive axle, what truck is that on? And how does it work?


PJA

iva cosworth

44,044 posts

170 months

Tuesday 12th March 2013
quotequote all
pja said:
As has been said, it saves on tyre wear, brake wear, fuel when unladen
Also I think there is or used to be a road tax saving as well??

Iva cosworth
I've never seen a lift drive axle, what truck is that on? And how does it work?


PJA
It's a 26 tonne ,6 wheel Daf.

If for instance you are manoeuvring on uneven ground the drive wheels could lose traction,you can press a switch

And the 3rd axle drops then press another switch to engage drive to this axle which I now call 4wd,sort of.

I have driven this truck about 5 times in 6 years.

JohnnyJones

1,758 posts

185 months

Wednesday 13th March 2013
quotequote all
^^ Never seen anything like that. You got a pic?

Humper

946 posts

169 months

Wednesday 13th March 2013
quotequote all
JohnnyJones said:
^^ Never seen anything like that. You got a pic?
Me neither? Pics please.

thismonkeyhere

Original Poster:

10,731 posts

238 months

Wednesday 13th March 2013
quotequote all
s p a c e m a n said:
Because we like toys biggrin
The real reason ^^

I suspected as much.

hehe

smifffymoto

4,771 posts

212 months

Wednesday 13th March 2013
quotequote all
Sounds like a cross lock or diff lock iva cosworth is decribing

pja

270 posts

232 months

Wednesday 13th March 2013
quotequote all
What he is discribing is a lift axle that also driven by the engine
I've been around wagons all my life and its not something i've ever seen or thought was possible!

I think it will be a standard 6x2 rear lift with a diff lock on the (middle) drive axle that when engaged gives him better traction on rough or muddy ground,
If this is the case he would be better to leave the lift axle up in these situations to add more weight to the driven axle

happy to be proved wrong though!
PJA

iva cosworth

44,044 posts

170 months

Wednesday 13th March 2013
quotequote all
Sounds like PJA knows more about this system than i do.

Now he has explained it i am not sure that the 3rd [lift axle] has drive to it when you

press the switch but it certainly assists if you lose traction on the drive wheels

when reversing or manouvering.

It's going on the 28th not going to be replaced due to lack of usefrown

I will go and find the one pic i have of it .

iva cosworth

44,044 posts

170 months

Wednesday 13th March 2013
quotequote all


It's nothing specialconfused

Pic taken after loading at Creeksea,Essex full of packs of plywood.

Edited by iva cosworth on Wednesday 13th March 22:13


PPS,I am not "Quackers" as this is not my usual truckhehe

Edited by iva cosworth on Wednesday 13th March 22:14




pic restored to thread after i moved it in photobucket who deleted it from here

Edited by iva cosworth on Sunday 7th April 02:11

pja

270 posts

232 months

Wednesday 13th March 2013
quotequote all
Thats a nice straight truck! What year is it 07/08?


PS
Have they got a buyer for it??

PJA

iva cosworth

44,044 posts

170 months

Wednesday 13th March 2013
quotequote all
That pic is a few years old now.

I kid the usual driver on the amount of steps he smashes up.

I might have walloped the rear bumper too on one of the 5 times i drove it.

It will be going back to HTC Croydon on 28th March,where it goes after that ,dunno ?

Not sure on mileage but it's not huge for a 5.5 year old,maybe 200K.

GC8

19,910 posts

197 months

Thursday 14th March 2013
quotequote all
Ive never seen a six wheeler with a lift driven axle before. In fact, I dont think that Ive ever seen a six wheel rigid which had a lift axle.

A 'five wheeler' (essentially a four wheel vehicle with a single wheel lift axle, upping the weight to 25 tonnes) configuration is far more common, I think.

s p a c e m a n

11,002 posts

155 months

Thursday 14th March 2013
quotequote all
PARRP hehe

pja

270 posts

232 months

Thursday 14th March 2013
quotequote all
iva cosworth said:
That pic is a few years old now.

I kid the usual driver on the amount of steps he smashes up.

I might have walloped the rear bumper too on one of the 5 times i drove it.

It will be going back to HTC Croydon on 28th March,where it goes after that ,dunno ?

Not sure on mileage but it's not huge for a 5.5 year old,maybe 200K.
Haha, I thought the corners looked a bit "untouched"

pja

270 posts

232 months

Thursday 14th March 2013
quotequote all
GC8 said:
Ive never seen a six wheeler with a lift driven axle before. In fact, I dont think that Ive ever seen a six wheel rigid which had a lift axle.

A 'five wheeler' (essentially a four wheel vehicle with a single wheel lift axle, upping the weight to 25 tonnes) configuration is far more common, I think.
Most six wheel rigids will have a lift axle unless they are double drive (6x4) and they tend to be tankers or tippers etc

Daf is one of the few that have double wheels on the rear lift axle , the ones with single wheels at the rear tend to steer as well
Iva cosworths CF in the picture will plate up to 26t and probably is

Pja