Two driving instructors who do driving assessments
for the haulage company’s they worked for told me
when winding the legs down to leave about a 1 inch gap.
The first time I heard this I thought It don’t sound right
as the trailer would drop down and then when the
second person said it got me thinking why they do it.
I learned class 1 by lowering the legs until they touch
the ground and will carry on using this method.
In the good old days of steel springs it might have meant that you were sure the trailer was low enough to make sure you got it on the fifth wheel properly. Although if you had loads of weight up front, the neck of the trailer would drop by much more than and 1" and you’d end up winding the legs to lift the trailer high enough to even get it on the skids, when you hooked it up again.
With air suspension lower the legs to the ground and drop the unit slightly on the way out and then lift the unit on the way in.
with the suspension at ride height, i always drop the legs as far as they will go (including pushing the handle to the smaller cog) and pull out. there is nothing worse than trying to get under a trailer that has been dropped too low. the other day i had to force an Axor under a fully loaded trailer and i got a bump on the head for my efforts
I always lower the legs to the ground with the suspension at normal hight and can see no logical reason for not doing so, I had to do a driver assessment last week and nothing was said about me lowering the legs all the way down.
The reason I was told by my instructor to wind the legs down to the point where the legs are just touching the ground is so that on your re-coupling excercise, you’ll pick the trailer up slightly and if you’re not straight, when the trailer moves to one side as you go under, you won’t bend the legs and fail the test.
Like most of the above I always wind them all the way down then drop the air on the unit once the pin is disengaged. When I am picking up a new trailer I tend to go under with the suspension low and then raise it until the legs are off the floor before I push back for the pin… …
scanny77:
there is nothing worse than trying to get under a trailer that has been dropped too low.
I’d say it’s ‘swings & roundabouts’, Richie.
A tlr that has been dropped too high (when loaded) can be equally as difficult to wind down as up.
It’s all quite ‘irrelevant’ nowadays though, what with air suspension!
I used to leave a gap from the legs to the floor but now wind all the way down and then back half a turn, and lower the air suspension to take the strain.
How much do you reckon a set of ski-ramps weigh?? Must be tempting to do away with them if weight is an issue.
I always leave at least an inch, if not 2, if I remember I then drop the air out of the unit to lower the trailer the rest of the way, if not just pull out slowly and trailer will descend rather then drop.
The main reason I do it is so that when I or another pick up the trailer you know you have got it. Lots of lights on units get smashed because of people leaving the trailer too high and then others reversing under it and missing the king pin. Leaving an inch saves alot of damage to units.
There is a reason for dropping a trailer with the legs slightly off the ground, it is easier on the steel springs as the weight is gradually taken off the leaves. It can also save a lot of broken springs in cold weather.
With air suspension the correct way is to drop the air from the trailer first. This stops the legs bending as the air leaks out of the rear bags
due to the fact i have a low height fifth wheel i always (even with an empty trailer) lift the suspension a couple of inches before winding the legs to the floor, then as i pull from the pin i drop the suspension down so the trailer is not resting on the unit at all.
if i drop a loaded trailer i lift the suspension on the unit, dump the suspension on the trailer and then wind legs to the floor, again i pull from the pin then dump suspension before pulling all the way out.
when i couple up i dump suspension then reverse under trailer, stop and lift suspension until the legs are off the ground, i then finish reversing under trailer, this allows (as already said) the trailer to move sideways without putting pressure upon the trailer legs if the tractor isn’t lined up correctly.
Coffeeholic:
Drop legs all the way, pull forward a little to disengage pin, drop air on unit then pull clear.
Thay’s how i do it,also when picking trl up i lower the 5th wheel and once i’m under i raise the 5th wheel till trl lift’s of ground then engage 5th wheel to king pin.Raising the wheel’s slightly off the ground ensure’s you don’t have trouble lifting leg’s incase trl is heavy.
Coffeeholic:
Drop legs all the way, pull forward a little to disengage pin, drop air on unit then pull clear.
You’d be amazed the amount of drivers who don’t.
I quite often stop at Cherwell Valley services on the M40 and there’s a firm in there every night doing a changeover,both of them just wind the legs down,pull the pin and give it some welly.
One night those air bags are going to pop!
You used to see that sort of thing quite often at Felixstowe when drivers were having loaded containers lifted off an air suspended skelly,on a couple of occasions the air bags did go pop.
After that they started fitted wire hausers between the axle and chassis.
scanny77:
with the suspension at ride height, i always drop the legs as far as they will go (including pushing the handle to the smaller cog) and pull out. there is nothing worse than trying to get under a trailer that has been dropped too low. the other day i had to force an Axor under a fully loaded trailer and i got a bump on the head for my efforts
Correction there is nothing worse than trying to pick up a loaded trailer thats had it legs wound down hard, only to find that when you come to pick it up the air has dropped out of the suspension, thus forcing the front end even higher, and tnat your unit is to low to pick it up even with your suspension fully raised. I’ve seen blokes raise the unit to drop a trailer and wind the legs down hard WHY . I leave the unit at its traveling height then drop the legs to just touch the ground, then pull away with the Coffeholic method…
If you pull atrailer with a deep pin like what we do you would not want to leave the legs up an inch when it is fully loaded. Watch how far the front drops down when you wind them all the way down anyway.
Depends on the weight, and the pin. if it’s very heavy and a deep pin, i’ll wind it on low for about 3-5 after it hits the deck. If its empty, i leave an inch or so, if it’s light, and a deep pin, i’ll wind it to the deck and maybe one on low. if it’s light and a shallow pin, to the deck will do.
. I leave the unit at its traveling height then drop the legs to just touch the ground, then pull away with the Coffeholic method… 
