For you class A guys, what would cause a trailer to drift to the right or left when being pulled at ~50mph on a straight road?
Posted by Metal-Alligator@reddit | Truckers | View on Reddit | 21 comments
I’m a class B driver so trailers and stuff are an enigma to me. When I was heading to the landfill the other day I was behind an 18 wheeler and the trailer kept drifting to the right, the cab was going straight but I was looking at the left side of the trailer as we went down the road.
justdan76@reddit
Operator error
Jimlee1471@reddit
Your description makes it sound like the trailer was "doglegging" (some people might call it "dog tracking"). That's when the alignment on the tandem axles are way off. No bueno for the tires, fuel mileage or handling.
BaseballDue9043@reddit
Usually caused by drivers jumping curbs on right turns and knocks the tandems out of alignment.
steeeevorino@reddit
Dry fifth wheel will exacerbate dogtracking.
Rikishi6six9nine@reddit
Misalignment. A lot of the chasis I pick up from the railyard are poorly maintained and often have issues like that.
Intelligent-Site7686@reddit
Tandems out of alignment... if you do a lot of drop and hooks maintenance gets overlooked and you end up at some point inheriting a rusted piece of shit that's pulling way crooked, bald tires, abs light on, bad brakes, etc. Wind might blow a light trailer around, but it straightens out when you're out of the gusts
Questionoid@reddit
1) trailer alignment in relation to: 1a) kingpin, one or both axles out, 1b) trailer axle bent, 1c) frame damage 1d) suspension or subframe damage 1d) bushing wear 1e) all of the above 2) crosswind
weebdiffusion@reddit
Ah the mail box smasher 9000
MoekenTroll@reddit
Driving empty and wind even at 5mph is enough to cause it
TruckerBeetleBailey@reddit
It could be an optical illusion in your mirrors, it could be that the alignment of the trailer is out of whack, it could be that the alignment on the truck is out of whack and it just looks like the trailer is coming around the side of you.
AnnulMe@reddit
I just dealt with this, old trailer and fucked up load combined.
FWD_to_twin_turbo@reddit
Out of alignment, i'd bet my left asscheek the bushings are shot.
Either that or buddy had some sweet, sweet crosswind / road lean.
Equivalent-Pride-460@reddit
Torque arm bushings?
FWD_to_twin_turbo@reddit
Not always, could be those pesky narrow beam bushings if it's an air ride trailer, could be the leaf spring bushings, the pivot bushings, or end pads if it's end dump style.
The endless joy that is suspension issues
Sufficient_Wall5192@reddit
Dog tailing, wind, empty trailer, or a torque arm out of adjustment.
Key-Mycologist-7272@reddit
That's called off-tracking and it's usually caused by the trailer not being in alignment which can happen over time and means they need to be serviced. How the load in the trailer is distributed can also cause it to some degree, as can high winds pushing the trailer while the tractor is driving down the road. A couple inches of off tracking isn't abnormal or cause for concern but once it starts getting to be half a foot or more it needs to be addressed soon and anything close to or past a foot that's not being caused by wind needs to be addressed immediately.
Metal-Alligator@reddit (OP)
That’s probably it, I hope he was taking to get serviced. Cuz I forgot to mention there was only a slight breeze that day. And even I could see it was definitely drifting more than a foot to the right.
One-Hold1340@reddit
It could be a lot of things or just one thing. The weight of the tractor and trailer make it impossible to tell exactly what’s causing it because of how everything works in conjunction with each other.
Siena2@reddit
Wind could be a factor, especially if they're light.
Metal-Alligator@reddit (OP)
Wind was calm that day, like a slight breeze all day.
carne_asada368@reddit
Wind + light or empty trailer