hi i’m new on here and after advice i just started driving a auto man tag axle arctic but i am having trouble getting out of work yard with a loaded trailer
it is uphill and a z bend getting out and it either wheel spins and staulls or if i dump the air i’ve got no steering after advice on how to get out in 1 so my boss doesn’t give me ■■■■ lol
Right 1st press tag lift button and raise axle
2nd pull off slowly or tag will lift and keep it in manual setting changing gear when you feel it needs to
Also what make of tyres you got on drive axle ? sound like you’ve got ditch finders like my unit has
Three things to getting an MAN going like this (or any other artic with air dump available), and i presume you mean a mid lift axle not a rear tag?
First as said above, assuming you are loaded dump the tag air, that’s the switch with the umbrella type emblem, (not the other switch that raises the axle it will not operate if the unit is heavy), after about 20 seconds the mid lift will raise fully…this is unique to MAN’s i believe as most air dumps won’t fully lift the axle…above 20kph this air dump facility automatically cuts out.
This is a handy tip for pulling away on damp roads too, it also makes maneuvering easier and cuts down on tyre wear on the tractor in yards.
Secondly, find and press the ASR button (on other makes this might be the TC button), when you do ‘driving offroad’ will come up on the dash…this will prevent power being cut when the vehicle detects any wheelspin, also helps protect the clutch in such situations as each time the vehicle cuts power at such slow speed the clutch disengages meaning a another full power clutch engagement on a hill…remember to press the switch again as you will no longer have traction control once out on the open road.
Thirdly, as said you are better off putting it in manual so arsetronic doesn’t try to change gear at the wrong moment…which is almost certainly causing the engine to stall because by the time it’s sent off for a free sample and found the next gear you have lost any speed gained and it dies.
After all that, if traction is a real problem regularly have you split weighed the tractor and trailer on a weighbridge to make sure there is enough weight being imposed on the tractor?
Whether you can do anything about such an issue depends on what your work is of course.
cheers but it is rear tag . first one i have ever driven and i can’t get to grips with it
Any room to move the fifth wheel? Or is the trailer headboard already close to the unit?
markyboyiow:
cheers but it is rear tag . first one i have ever driven and i can’t get to grips with it
Basically it should be similar (except you should get a lot more grip on the drive axle with a tag), there should be an air dump valve, and the rest (ASR/Manual mode) will still be the same.
I wonder if the air dump/tag lifter isn’t working, check that first …or did it come without air dump facility from the converter…we had a similar issue with aftermarket mid lifts on FM Volvos which stupidly came without air transfer valves 
can’t move the fifth wheel any closer as use different trailers all the time it has got air dump but it takes all the weight off the front axle and can’t steer it
There should be a weight transfer button that you hold in for as long as you need to apply extra weight on your drive axle. Take finger off button when you feel you have enough traction to keep going. The button takes some weight off the tag without lifting it entirely off the deck. Been a while since I’ve driven a MAN so can’t remember what the button looks like, but it had a tag axle and I remember using it on a steep hill.
Ask one of the other drivers in the yard in the morning? they’ll keep you right…
none of the other drivers any help they only drive. midlift the guy who had it before me left the yard empty on a monday and came back friday but he left i tried dumping air turned off asr locked it in manuel and still had no steering going round second bend. my boss even had a go and did the same
if i don’t dump air it steers but then spins if i dump the air front end lifts and goes straight towards the bank
Thats a pain in the arse.
Unless you can move the fifth wheel forward enough to get some steering back, about the only solution i can see is to get a manual dump valve with a lock position piped in to the cab, or some alteration made to the existing dump valves so you have some sort of manual control, so you can let just enough air out of the tag airbags to do the job, unless with a bit practice and good timing you can dump/refill the tag air at the right moments to make the turns.
These modern vehicles it’s all or nothing and you need a half way solution, going into winter you’ll have this problem more often than just at your yard exit.
Alternatively can you do anything with the trailer? ie assuming a triaxle does it have a front lifting axle, if so does it have a manual lift valve and does this axle lift when loaded? i’ve had the odd trailer that would lift when loaded and another that would lift loaded if i lowered the suspension…not as you’d go sailing up the road like this but it might be another thing to check to get out of a slippery situation.
Nothing you can do load wise to get more weight up the front of the trailer?
One other thought, the bloody diff lock isn’t permanently stuck in is it?
All good advice…
It begs the question why do vehicles with such dreadful traction continue to be built? I can’t imagine that MAN or Iveco have videos of their flagship truck struggling to get up a molehill sized pimple in a yard, whilst displaying them under spotlights with fleet salesmen around them at the big truck conventions.
I always assume that what ever I’m driving is going to make me look a plum in the rain before I set off so I’m already in manual, switching off auto-■■■■■■ devices, pushing harder or dropping off before the whole thing stops and starts spinning. I did get caught out once some years ago on a really steep hill near Bradford airport in an Iveco. ■■■■ thing just gave up near the top all I could do was stop and set off again with the dif-lock in and even that was a fight.
Juddian:
Thats a pain in the arse.Unless you can move the fifth wheel forward enough to get some steering back, about the only solution i can see is to get a manual dump valve with a lock position piped in to the cab, or some alteration made to the existing dump valves so you have some sort of manual control, so you can let just enough air out of the tag airbags to do the job, unless with a bit practice and good timing you can dump/refill the tag air at the right moments to make the turns.
These modern vehicles it’s all or nothing and you need a half way solution, going into winter you’ll have this problem more often than just at your yard exit.
Alternatively can you do anything with the trailer? ie assuming a triaxle does it have a front lifting axle, if so does it have a manual lift valve and does this axle lift when loaded? i’ve had the odd trailer that would lift when loaded and another that would lift loaded if i lowered the suspension…not as you’d go sailing up the road like this but it might be another thing to check to get out of a slippery situation.
Nothing you can do load wise to get more weight up the front of the trailer?One other thought, the bloody diff lock isn’t permanently stuck in is it?
Without wishing to be rude this begs the question whether you have identified the air dump switch correctly and not selected diff lock instead? Most unlikely since you should have heard air hissing. Traction control cuts the throttle and brakes the spinning wheel it should still leave steering control.
Even if the trailer hasn’t got a lift axle raising the suspension on the trailer will certainly impose more weight on the unit, possibly just enough if everything else is left alone? The drawbacks being catwalk clearance when turning and how long it will remain up once you start moving; you can check both in the yard 1st though.
yourhavingalarf:
I did get caught out once some years ago on a really steep hill near Bradford airport in an Iveco. ■■■■ thing just gave up near the top all I could do was stop and set off again with the dif-lock in and even that was a fight.
Last one i drove the driver had no control of the mid lift axle, and saddled with the worse programming of arsetronic its been my displeasure to use, so not a surprise at all that you struggled with the heap, i was happy to see the back of it.
edit, one final thought for the OP, if you have access to a weighbridge (axle weigher best, but if you weigh the loaded tractor unit only on a standard bridge and then reverse the tag axle off and reweigh you will have the figure you need) i wonder if the tag is getting too much air and taking too much weight off the drive axle…easily checked if you have a weighbridge you can use for a couple of minutes.
I mention this because with mid lift MAN’s the position of the fifth wheel is vital to correct loading of the mid lift so the same will likely apply to the tag, if the fifth wheel is too far back the mid lift (especially small wheeled ones) can be slightly overloaded…i know it sounds weird that moving the wheel back loads the mid lifter, but trust me its true, i spent several days perfecting the fifth wheel position on my then new tractor unit, worth checking out.
Not read the other posts, but is pointing it in a straight line with the tag lifted, in manual, low gear, use high revs but mid throttle position, then just before you need to turn drop the tag so get your steering back, if it’s still pushing the front, because of the high revs you’ll be able to lift off slightly which will give a weight transfer to the steer axle and give you more grip for steering.
You may then if drive axle traction is an issue have to raise the tag whilst pointing straight and repeat the process
If you’re having traction issues with the tag down then it’s turn off traction control and put diff lock in whilst you’re going straight, there’s no problem with putting diff lock in / out whilst on the move, so long as both drive wheels are turning at the same speed
thanks for all your advice it seems to b trial
and error i dumped the air just as i was goin to turn
and managed to get out dreading the winter
o for a midlift so much easier
And then when you get going wait for the propshaft to snap as they do on most MAN tag axles, one of the reasons they stopped making them for a couple of years and now they will only off them upto 500bhp, notoriously bad design, wheelbase is too short so the props at the wrong angle
I would check that when your dumping the air the skids on the fifth wheel are not going inside the trailer chassis. Had an Erf used to do this when going uphill out a yard onto road it wouldn’t turn left. Also read that don’t dump air but put it at high as you get more weight on drive wheels.
chaversdad:
And then when you get going wait for the propshaft to snap as they do on most MAN tag axles, one of the reasons they stopped making them for a couple of years and now they will only off them upto 500bhp, notoriously bad design, wheelbase is too short so the props at the wrong angle
Spot on that man! For some reason best known to themselves, MAN do not offer a tag axle unit in the UK with a wheelbase greater than 2.9 metres.
The result of this is propshaft issues, as the angle from the gearbox flange to the diff flange is to steep.
Having said that, they are quite popular in this part of the world, with some quite big fleets of logging trucks on the road. They buy them (tags) particularly for the much better traction and maneuverability which this configuration offers compared to midlifts
This is not helping you though, and without really knowing what you are doing and what kind of loads you are carrying,it’s difficult to know what to suggest. I’m inclined to think though that the fifth wheel is maybe too far back on the chassis. You will be surprised bythe difference to the vehicles handling which will be obtained by moving the fifth wheel forward by as little as 100 mm. I had a Volvo FM a while back, which, when I got it, handled like a pig and wanted to go straight on at anything other than a slight bend. I took it to a dynamic weighbridge (loaded) and weighed the individual axles. Then moved the coupling forward by 100mm.The result was to impose another ton on the steering axle, hard to believe but true.
After what seemed a pretty minor adjustment it was probably the nicest handling the truck I have ever had.
