Only ever seen older drivers do this, but when I had to pick up a trailer that was very heavy so it was “bent down” slightly forward of the legs, the driver had dropped it with legs off the floor making it even lower, I could not get under it. In the end had to take a decent run up and just ram it under with an almighty bang.
Given that I’ve only seen older drivers do it like this I’m guessing there’s some reason for it?
DickyNick:
Only ever seen older drivers do this, but when I had to pick up a trailer that was very heavy so it was “bent down” slightly forward of the legs, the driver had dropped it with legs off the floor making it even lower, I could not get under it. In the end had to take a decent run up and just ram it under with an almighty bang.Given that I’ve only seen older drivers do it like this I’m guessing there’s some reason for it?
Well its not all older drivers who do this.As i’m one.And never have dropped a trailer like that.Don’t see the point to it.
Sent from my SM-G950F using Tapatalk
In the “good ole days” before units had air suspension, it was considered good practice to leave an inch for the trailer to drop. This meant that when anyone went to pick the trailer up, there was a good chance that the trailer and the fifth wheel would be in firm contact. Missing the pin altogether was an all too frequent and costly error.
In a unit with air suspension, it should have been easy to take the weight off the legs so that you could wind them down. Have you ever wondered why there is a low ratio on the leg winding mechanism?
The secret is not the distance you leave the landing legs raised but speed at you pull from under the trailer can make a huge difference !!!,
It’s an old fashioned thing. Even with air suspension a standard thing now, you still see the dinosaurs slamming under trailers with the run up ramps. Just puts totally unnecessary wear & tear on the kit and gets grease everywhere.
Not sure I’d have just slammed under the trailer like the OP. Better way would be to drop the air right down on the unit, then drop the air suspension at the back of the trailer too, if still too high then wind the legs down a bit on the low gear. Wouldn’t take long to get the height right.
The reason for dropping the trailers with legs an inch or so off the floor was to help prevent broken leaf springs.
The theory was that in cold weather, banging under a trailer could bend the springs and snap them. I have never broken a spring or a helper so can’t say if it helps or not.
What I do remember though is a 33’ or 40’ trailer didn’t bend in front of the legs, and winding the legs down for a high unit in low gear.
they had a date with wilmam flintstone. ■■■■■■■ tool should have got a smack
rob22888:
It’s an old fashioned thing. Even with air suspension a standard thing now, you still see the dinosaurs slamming under trailers with the run up ramps. Just puts totally unnecessary wear & tear on the kit and gets grease everywhere.Not sure I’d have just slammed under the trailer like the OP. Better way would be to drop the air right down on the unit, then drop the air suspension at the back of the trailer too, if still too high then wind the legs down a bit on the low gear. Wouldn’t take long to get the height right.
I tried it all bud. The trailer was on a slope pointing down as well but the point at which the unit went under was level ground so that wasn’t helping either, loose ground as well so wheels just spinning, air as low as it would go. I didn’t wind the legs, but even in low gear would it move with that amount of weight on? Anyway the driver who dropped had done it like this with the legs off the ground. When I’m dropping one with so much weight I raise it up a little at the front never mind making it even lower so it makes it easier for the next driver to get under, and so it doesn’t bang as hard on the run up ramps as the unit comes out from under it. As long as every driver follows the companies procedure which is go under, then raise your air all the way up so the legs leave the ground, and then hit the pin, no one should ever be missing it.
The reason trailer legs where or are left “short” is that when the trailer was /is loaded, and a unit is put underneath the strain is taken off winding the legs up.
Many on here will tell you before air suspension it was common practice to sweat your “nuts off” trying to wind trailer legs up because the unit did`nt lift the trailer high enough because of the load weight. These days most have a proper shunt tug but not so long back it was a “old knacker” of a normal road unit which could only dropped or pickup at one height,irrespective of what was taking the trailer out.
There’s no hard and fast rules here, anyone with an ounce of common sense makes the drop height sensible for what is most likely to happen to the trailer before the legs get wound up again.
ie
dropping an empty which is going to be picked up empty again, take into account what vehicle you have and what could pick it up next time and make allowances if the next vehicle might be much lower…less chance of missing the pin entirely for those who reverse straight under on mirrors alone 
those who insist on leaving the Scania tag up seem incapable of thinking about the next driver.
dropping an empty which a tug is going to pick up and drop before loading heavy (tug driver won’t touch the legs), then right down to the ground and if its a long overhang curtain likely to bend at the front when loaded make sure it’s sensibly high
dropping a regular trailer just before your tractor goes for overnight service, leave it high enough so nights (if applicable) don’t scrape all the fresh grease up the front of the rubbing plate
dropping an empty without allowing the fifth wheel to angle correctly by sliding straight out, thereby leaving it horizontal, can see the next driver ramming the rear of the fifth wheel up the front of the trailer if the driver doesn’t adjust suspension, at one RDC one morning the full timer picking the trailer next door must have had 6 rams at the trailer, each time taking a further layer of paint and steel off the panel above the rubbing plate, they might still be working their way through as we speak if i hadn’t pointed out what was happening.
Yes in times gone by leaving as much as 3" gap when dropping an empty was regular thing, thankfully trailers didn’t bend like they do now (and they lasted years longer), some trailers didn’t have two geared landing legs, so no option.
It was done in my experience when trailers were Shoehorned together in rank and you couldn’t get to the winding handle.
You got the ‘Early Risers’ under the trailer which lifted the trailer that bit off the ground then, do the ‘tug test’ then put your red air line on to pull the trailer out far enough to get to the winding handle - easier still if you had wheels instead of feet on the landing legs !
DickyNick:
Only ever seen older drivers do this, but when I had to pick up a trailer that was very heavy so it was “bent down” slightly forward of the legs, the driver had dropped it with legs off the floor making it even lower, I could not get under it. In the end had to take a decent run up and just ram it under with an almighty bang.Given that I’ve only seen older drivers do it like this I’m guessing there’s some reason for it?
You can always lower the rear of the trailer using the colas valve which in turn will raise the front of the trailer slightly, you don’t really want to be taking long run ups and having almighty bangs as you put it .
another reason…
“in the old days”, when trailers were on leaf springs…
the legs were a pivot point.
so dropping a trailer with the legs wound fully down ready for loading, the weight would push the springs down , that would make the front end pivot upwards, resulting in missing the pin or doing a lot of leg winding…
Trukkertone:
another reason…
“in the old days”, when trailers were on leaf springs…
the legs were a pivot point.
so dropping a trailer with the legs wound fully down ready for loading, the weight would push the springs down , that would make the front end pivot upwards, resulting in missing the pin or doing a lot of leg winding…
^^^
The same thing is true still. If the trailer is on a loading bank and will be loaded with an electric truck or forklift then the air keeping the bags at running height is going to get used up with the continual weight going on and off.
Some of the less grey drivers may like to practice winding a trailer up from the bottom, if you didn’t have a suitable handle or the next trailer was tight up, you use a screwdriver [emoji14]
I have seen the “almighty bang” to hitch up to a trailer result in shearing the pin clean off.
An almighty bang is the result of poor throttle/clutch control in a manual or poor throttle control in an auto. If coupling up to a low trailer in an auto try covering the foot brake with your left foot. It isn’t precise and it’s certainly not elegant but it’s a ■■■■ sight better than emptying the overhead lockers onto your lap.
If the trailer is loaded, then I would suggest winding the legs all the way to the floor. If the trailer is empty, then I would advise winding the legs all the way to the floor. 
Winseer:
If the trailer is loaded, then I would suggest winding the legs all the way to the floor. If the trailer is empty, then I would advise winding the legs all the way to the floor.
What if its half loaded ■■ Lol
Trukkertone:
Winseer:
If the trailer is loaded, then I would suggest winding the legs all the way to the floor. If the trailer is empty, then I would advise winding the legs all the way to the floor.What if its half loaded ■■ Lol
In that case you wind them halfway down to account for the half load, then the same distance again to account for the empty half of the trailer. Experienced drivers can estimate the proportion of a full load being carried and wind the legs down by just the right amounts to account for the loaded and empty parts of the trailer. It’s a good demonstration of the drivers’ skills as the legs reach the ground every time even though they don’t use any modern technology to assist in the calculation. A top driver can even do the reverse calculation in his head when lifting the legs, leaving them right at the top of their travel each time he coupled up a trailer.