As some of you may or may not know,ive just had my first week on the bendy toys. All the units at our place are 6x2 and all the trailers are tri axle curtainsiders 40’.
Some of the trailers have the rear-most axle that lift,although I haven’t ’ activated ’ it,i assume its on some kind of load sensor.
Can I lower this axle? I know about the lift axle on the units and where the button is etc.
I noticed on a run back from Leicester last week that my truck was really sensitive/twitchy on steering inputs. Got to the lights and lowered my unit axle and this obviously improved things. The axle on the trailer was up as I was empty. Why is it so twitchy when BOTH axles are up? Or is it that I have got used to a ’ best case scenario ’ by running with 6 axles on the deck?
There is certainly a different feel to the steering with a rigid which has a lifting tag-axle. The limited number of times I have driven a tag tractor I have noticed the same thing. However it is normally these days the centre axle of a tractor unit which lifts. It will depend on whether this axle steers or not on what difference you will feel if it is raised. If it is non-steering you will no longer be feeling the drag and the feeling of wish to carry straight on when it is up, this may appear to you to be twitchy but you will get used to it.
I’d get used to lifting the (usually) mid lift tag on a tractor whenever the vehicle is light enough, they can be skittish (wheelspin especially) with the axle down in the wet.
As Cav mentions, non steer mid lifts make the vehicle less steering responsive than steered mid tags.
Juddian:
I’d get used to lifting the (usually) mid lift tag on a tractor whenever the vehicle is light enough, they can be skittish (wheelspin especially) with the axle down in the wet.
As Cav mentions, non steer mid lifts make the vehicle less steering responsive than steered mid tags.
I noticed that. I was doing a drop on a hill for a paper place. When I was done I tried to reverse it back up a curb and it was having none of it. Lifted the tag axle before it would actually move.
Thanks guys. Both the DAF XF and the SCANIA R480 ive been driving are mid axles. I know the DAF has a steering mid lift but I have a feeling the SCANIA isn’t. (I will check it out for sure tomorrow).
Whats the score with the trailers in your experience?
eagerbeaver:
Thanks guys. Both the DAF XF and the SCANIA R480 ive been driving are mid axles. I know the DAF has a steering mid lift but I have a feeling the SCANIA isn’t. (I will check it out for sure tomorrow).
Whats the score with the trailers in your experience?
I imagine it would be the same as the back end of a rigid. Just watch your tail swing!
Never had a rear axle lifting trailer that i can recall, those of ours that lift its the front that does, some have a switch some are auto but even with the switchable ones once there’s enough weight on board the axle comes down anyway.
I always lift them when possible, apart from dragging an unnecessary axle along it helps transfer a bit more weight onto the drive axle, however the opposite would be the case with a rear lifter but by a tiny margin, so would judge when it suited me to use that type.
Thanks Jud. I am gonna try and find out this week if possible which trailers are lift and which are not.
My current practice is just to ’ Grab any empty one '. I think a bit more diligence would be sensible. Obviously if im hooking up to a loaded trailer,as you rightly say,the axle will be down. So defo need to try and work out whats what.
Just don’t want to look and sound a ■■■ in front of the other drivers with all my rookie bellend questions!
eagerbeaver:
Thanks Jud. I am gonna try and find out this week if possible which trailers are lift and which are not.
My current practice is just to ’ Grab any empty one '. I think a bit more diligence would be sensible. Obviously if im hooking up to a loaded trailer,as you rightly say,the axle will be down. So defo need to try and work out whats what.
Just don’t want to look and sound a ■■■ in front of the other drivers with all my rookie bellend questions!
You won’t look a ■■■ mate, no bugger’s got a clue any more even after 15 years at the wheel, half the time my regular motor comes back from night runs with the tag still down…they must have some fun getting round damp salty roads, and i’m sure i’m the only one that knows how to raise the lifter on the few switchable trailers, so if you ran round permanently with the trailer axles all down i bet you first pint that 99% of your colleagues wouldn’t even notice.
I would always operate the tractor tag though if i were you, get into the habit…oh and learn how and up to what speeds it operates to dump the tag air via the switch with the pic of umbrella over the axle, that’ll help you no end on slippery surfaces such as pulling away without wheelspin at busy junctions and steep hill climbing in poor weather when loaded.
On the DAF if you operate that umbrella switch loaded you should find the tag lifts completely off the ground for as long as you need it to, that cancels as soon as you get up to about 20kph if you don;t drop the axle again once moving…have a play.
eagerbeaver:
Thanks guys. Both the DAF XF and the SCANIA R480 ive been driving are mid axles. I know the DAF has a steering mid lift but I have a feeling the SCANIA isn’t. (I will check it out for sure tomorrow).
Whats the score with the trailers in your experience?
Depending on the age off the Scania, pre 2012-ish will all most certainly be lift and steer as with the Daf, but newer Scanias are predominantly scrubber mid lifts(don’t steer) change in Scanias configuration policies, means that a steering mid-lift is now an extra, about £2500 extra so I was told
As for lifting axles, I for one get any lifting axle off the ground asap, except in very particular circumstances, as for the handling, yes it will be different, but that makes the difference between a driver and screw driver. Ride with it get used to it, and learn, but its always good to double check any changes in any characteristic of your truck, never assume its right just because it was before. Main thing is to get out and enjoy
Changes in handling when running light/empty with axles lifted are caused by a significant change in the wheelbase length (esp. on trailers and tag axle units) and less weight on the tyres, meaning they slide and bounce across the road surface far more easily. For many trucks, running empty requires far more concentration than running loaded and can be harder work as a consequence.
On a triaxle trailer, the centre/pivot point of axles is right in the middle of the central axle, but with the rear axle lifted the centre point would move forward to between the 2 axles in contact with road, shortening the wheelbase, creating more tailswing and with less tyre friction, causing the trailer to turn more quickly.
Regarding manually lifting/lowering the lift axle on a trailer, there is commonly a push pull switch like the trailer park brake and shunt switch in the same area, usually push to lift, pull to lower. Depending on the age of the trailer this could be automatic via a load sensing valve, manual lift/auto lower or fully automatic. Best to give these things a good eyeball when doing your walkround checks when picking up the trailer to avoid overloading by running fully loaded with a lift axle up and having a blowout as a result. Hope this helps.
eagerbeaver:
Top answers chaps-im grateful. Don’t mind that much looking a ■■■. Thinking about it,ive spent the last 42 years perfecting the art.
Hah, another good few years on you then, and i’m an olympic gold medal standard ■■■, by the time you’ve caught up i’ll be retired or kicked the bucket…hope its the former i want some of my money they took forcibly back in pension…course if i end up in the tender mercies of the Hammer House of NHS they’ll probably stuff me outside in a freezing corridor like they do other poor old buggers in order to cull the numbers.
EBGBz-cracking answer mate-thanks. Its amazing how much you DONT get told about the job!
I will have a good mooch in the morning at some trailers and will post on here tomorrow with any findings as it may well help others in my stained ■■■■■■■ position.
There’s no standard layout or function to a lot of the features on trucks, and it leaves so many of us properly confused. Best plan is to check repeatedly and when that fails ask another driver who you know has had experience with the same equipment.
eagerbeaver:
Top answers chaps-im grateful. Don’t mind that much looking a ■■■. Thinking about it,ive spent the last 42 years perfecting the art.
The SCANIA ive been trusted with is a 62 plate,so that ties in with what you have said, Im sure it doesn’t steer.
Ok mate a good piece off equipment there, I’m currently piloting a 13plate R440, but have used numerous scanias over the years, but this is 1st that is not a steer and lift putting aside a tag axle P112 to many yrs ago. Here something you may like to consider, adjacent to the unit lift/lower switch and diff lock, is a weight transfer switch(dumps the air from the midlift axle), If you have the axle down and lose traction this will aid you to get grip again at low speeds, it will only function at low speed. I also use this to minimise tyre scrub when manouvering in premises or on tight junctions, as I’ve found that the scania scrubber is a bit prone to wheel spin, well compared to previous lift and steer axle scanias I’d used Hope that’s off use mate
Eddie-that will explain the constant wheelspin the other day when I took one of the brand new 15 plate units for its first drink of diesel. (£450 EEK!!). Bloody thing was wheelspinning like a dodge charger. Even with a gentle right foot!!
