Last night on a few (dozen) occasions I had my truck go a bit … wobbly. At first I thought it was an uneven road surface but I’ve been up and down that road quite a few times and don’t remember it being so bad before. I looked at the trees but there was no wind either. Then I realized it’s most likely ice as it was only +2 degrees and there were patches of fog. I’ve been driving for 2 years but never had a truck behave in such way. Tyres were good, excellent even - the truck has only about 15 000 miles from new, the ones on the trailer were very good too. Middle axle was down for ‘‘optimal traction’’ according to the computer, I didn’t see the anti-skid system activate at any point (yellow flashing light). I should mention I was empty and in a Renault which I’ve noticed (on previous occasions) is very susceptible to even a light side wind causing me to wrestle with the steering wheel to keep it straight.
I dropped my speed to 50mph so I could better react to these rather violent wobbles but other trucks seemed unaffected and kept going at their max speed. At one point I got seriously scared on the A42 I literally felt the truck slide for a second and that was with the trailer loaded. All in all a very stressful drive. Sudden gusts of wind? Ice? Or just the way the Reanault is designed? It’s only the 2nd time I’ve driven this truck (70 plate).
I’ve driven in all sorts of weather including snow fall with snow covered roads etc. (admittedly rigids not artic) never had this happen before. Are artics more susceptible to sliding/wobbling I guess is my final question
Mid lift should be up in empty or lightly loaded conditions, by running with the mid lift down you are reducing the already low 4ish tons on the drive axle by probably a ton.
I presume you have control over the mid lift and it isn’t like that poxy Stralis i once was unfortunate enough to drive where the driver had no input whatsoever on the bloody extra axle, what chump thought that up?
Other things to check, tyre pressures, we run drive axles at 90 psi cos when loaded we run full weight, wouldn’t be surprised if your drive axle tyres are up around 105/110psi, doesn’t sound a lot of difference but the difference in grip will be even if 10psi over.
15000, those tyres are not fully bedded in yet, and if they are overpressure it can feel, in the words of my mate who decribed it perfectly, like driving a plate of spaguetti.
If they salted the road the night before, for no need as is so often the case, that salt the followiing nights attracts the moisture and forms a very slippery surface on the road, but to be so bad on a straight road i’m going for a combination of too high tyre pressures, the mid lift being down, exacerbated by new tyres not yet scrubbed the releasing agent off the tread.
If its as bad loaded, is the way the vehicle is loaded putting more weight on the trailer axles? it might be worth trying the vehicle with the mid lift up loaded, assuming you arn’t heavily loaded the mid lift won’t respond to your lift request if the weight imposed on the tractor is too much.
One other question, you haven’t got a trailer with a rear lifting axle have you, they don’t help this situation at all.
ETS:
Last night on a few (dozen) occasions I had my truck go a bit … wobbly.
. Middle axle was down for ‘‘optimal traction’’ according to the computer, I didn’t see the anti-skid system activate at any point (yellow flashing light). I should mention I was empty and in a Renault which I’ve noticed (on previous occasions) is very susceptible to even a light side wind causing me to wrestle with the steering wheel to keep it straight.
. At one point I got seriously scared on the A42 I literally felt the truck slide for a second and that was with the trailer loaded . All in all a very stressful drive. Sudden gusts of wind? Ice?
I’ve driven in all sorts of weather including snow fall with snow covered roads etc. (admittedly rigids not artic) never had this happen before. Are artics more susceptible to sliding/wobbling I guess is my final question
Have I read your post wrong ? Bit of a difference in your post there! Were you empty or loaded ?
Especially > Then I realized it’s most likely ice as it was only +2 degrees
Yep, this I’m afraid.
Nothing wrong with the truck, or at least extremely unlikely given it’s brand new. Some tyres are more susceptible to the tramlines than others and they are bad in places on the 42. When you get a clear bit of road with no traffic, move over into lane 2 and see if it’s still doing it.
You know, for a borderline loonie (regarding conspiracies etc.) you’re quite knowledgeable about trucking I think you’re right on the tyres + mid lift. The Renault has a button like most trucks with 2 positions up and down for the axle with middle being ‘auto’, however if you try to lift it manually (even when empty) you see a message ‘axle lifting denied’ so first you need to press another button which has a drawing of a weight hovering above the rear of 2 wheels, i.e. transfer the weight onto the rear wheel and you have to do it every time you start the engine or the axle will auto lower as soon as you turn the ignition on. I did the same route tonight in a Merc and yeah the road surface is pretty atrocious at some spots (A14 east + A11) but the Merc handled them much better than the frenchie.
pierrot 14:
Have I read your post wrong ? Bit of a difference in your post there! Were you empty or loaded ?
No, I should’ve clarified a little: I was lightly loaded on my way to the first stop, then empty on my way to the second stop, then loaded (not heavily) on my way home. Being loaded barely made a difference though bear in mind it was less than maybe 4-5 tonnes at most.
The main issue was with the unit, the trailer was ok pretty much.
p.s. (OT) has anyone seen trailer legs with WHEELS on the bottom? Isn’t that a bit counter-productive? No, I don’t have such but I saw a parked trailer which had them and I was baffled a bit.
ETS:
p.s. (OT) has anyone seen trailer legs with WHEELS on the bottom? Isn’t that a bit counter-productive? No, I don’t have such but I saw a parked trailer which had them and I was baffled a bit.
Yep, seen loads over the years. Used to be far more common.
ETS:
p.s. (OT) has anyone seen trailer legs with WHEELS on the bottom? Isn’t that a bit counter-productive? No, I don’t have such but I saw a parked trailer which had them and I was baffled a bit.
Saves ripping up the road on a vigorous ‘tug test’; although good pads will have a decent flange to prevent this too.
The leg wheels won’t rotate if the axle wheels don’t when parked so no issue.
ETS:
p.s. (OT) has anyone seen trailer legs with WHEELS on the bottom? Isn’t that a bit counter-productive? No, I don’t have such but I saw a parked trailer which had them and I was baffled a bit.
Yep, seen loads over the years. Used to be far more common.
So did seeing the wheels at the side of the road after they’d fallen off because some cross eyed driver couldn’t line up straight when coupling, causing a sideways force on the trailer as the pin found the jaws, which sheared the big but soft split pin that held the wheels on.
