Sometimes they just have to sit a long way back so the chassis doesn’t foul the trailer. You should have seen the dints & damage to front lower panel on this trailer!
Enjoyed this nice easy run from Fleetwood to Castle Donington with a rather unusual trailer for POFM to be pulling. 
Silver_Surfer:
I am surprised that moving the trailer back would put more weight on the back axle, I would have thought the opposite would be the case as their would be more of the load over the back axle the further forward the trailer..
when the trailer is right forward ther is more weight yes, but its split between the lift axle & the rear axle. if the trailer is right back then the weight of the trailer is mainly over the rear axle & not split between the 2.
BUT it is pointless moving the 5th wheel right back to aid traction if you have a lift axle or load transfer button as lifting the lift axle when fully loaded & trailer right forward will put more weight over the drive axle than the trailer being right back.
what trailer dous pull anyway?
cheers
Driveroneuk:
Sometimes they just have to sit a long way back so the chassis doesn’t foul the trailer. You should have seen the dints & damage to front lower panel on this trailer!
Enjoyed this nice easy run from Fleetwood to Castle Donington with a rather unusual trailer for POFM to be pulling.
What do you expect when it’s normal driver is a Dcpc trainer 
Makes sense truckers boy. You’ll also stretch your suzies and be more likely to pop one if it’s right the way back.
truckers boy:
Silver_Surfer:
I am surprised that moving the trailer back would put more weight on the back axle, I would have thought the opposite would be the case as their would be more of the load over the back axle the further forward the trailer..
when the trailer is right forward ther is more weight yes, but its split between the lift axle & the rear axle. if the trailer is right back then the weight of the trailer is mainly over the rear axle & not split between the 2.
cheers
How can it make the trailer heavier or lighter? The weight the trailer imposes on the tractor unit will remain the same. Only the axel weights on the tractor will differ.
ant2503:
i am looking for some advice regarding sliding 5th wheel. I recently drove a truck where the 5th wheel had been moved as close to the back of cab as possible? 1 of our other drivers said that it should be as far back as possible from cab in the bad weather as it will put more weight onto the drive axle, i am not sure on this. My boss has agreed with this other driver and is going to have all 5th wheels moved as far back from cab, in my opinion i would think this may overload drive axle if carrying heavy load and therefore have positioned mine centrally so the weight is distributed.
I don’t know for whats sliding Fifth Wheels are good other then getting a bigger Gap when coupling or uncoupling Trailers.
Truck Manufacturer give you exact place where kingpin has to be and its usually on the front-End of a Sliding fifth wheel.
if you move it back you change Balance on tractor from front axle to drive axle,and no weight on steer axle is last i need when slippery Condition. You may get the Bill in Case of accident.
well,and Fuel Consumption.
To have more weight on drive axle rises Fuel Consumption and slows you down.
Just think. If you will know how often your Wheel on drive axle turns in 90 kilometer per Hour you messure from middle of axle down,multiplicate Radius x pi x 2 and you have the Lenght of one Turn. if you get more Weight on drive axle your Tyre would be pressed more down and Radius gets smaller. So the Way the Wheel does every Turn is shorter,and it slows you down as Speed limiter let Wheel not running faster,but it has to turn more often to do 90 Kilometer,why you also need more Fuel.
And lorry is unstable,as less weight on Front axle
Funny thing I was talking with my boss about sliders the other day. Ive had loads of sliders but I think Ive only ever had to move it once in over 10 years. I reckon 95% of standard curtainsiders all have the pin in the same position. Ive always had them close coupled myself. I had a truck once from brand new till it was sold, the boss had paid extra for a low-profile slider and it never moved in the whole time we had it.
Moving the fifth wheel back to aid traction? Your boss does sound like a cabbage…perhaps an ‘office’ TM? Empty head. Dumping air, lifting mid-axle, lifting foot off gas, traction control off…try all of these ideas first before ■■■■■■■ about with a sliderto help traction in bad weather, FFS.
How does one slide the 5th wheel any way?
joedwyer1:
How does one slide the 5th wheel any way?
The easiest way is while coupled up pull the handle which releases the slider then move slowly backward to close the gap or forward to open it. While going backward you want to avoid hearing the sickening crunch of breaking plastic if possible or new rear light lenses will be required. If you can’t get under the trailer, because the wheel is in the wrong position and you will hit the landing legs before biting the pin, you pull the release handle then stand on the catwalk and kick [zb] out of the wheel and hope it slides back.
If you don’t fancy the kicking option you can go lower the suspension, go partway under the trailer and lift the suspension until the plate touches the trailer, don’t go too high so you lift the legs a long way off the ground. Then pull slowly forward and the weight of the trailer on the plate should make it move enough before you pop out from underneath and drop the trailer with a loud bang, hence why you don’t lift it too high.
Edit because I forgot to mention it. Make sure the trailer brake is on before trying to slide the 5th wheel.
Coffeeholic:
joedwyer1:
How does one slide the 5th wheel any way?The easiest way is while coupled up pull the handle which releases the slider then move slowly backward to close the gap or forward to open it. While going backward you want to avoid hearing the sickening crunch of breaking plastic if possible or new rear light lenses will be required. If you can’t get under the trailer, because the wheel is in the wrong position and you will hit the landing legs before biting the pin, you pull the release handle then stand on the catwalk and kick [zb] out of the wheel and hope it slides back.
If you don’t fancy the kicking option you can go lower the suspension, go partway under the trailer and lift the suspension until the plate touches the trailer, don’t go too high so you lift the legs a long way off the ground. Then pull slowly forward and the weight of the trailer on the plate should make it move enough before you pop out from underneath and drop the trailer with a loud bang, hence why you don’t lift it too high.
Pop the trailer brake button on, release 5th wheel, then move in either direction?
mickfly:
Coffeeholic:
joedwyer1:
How does one slide the 5th wheel any way?The easiest way is while coupled up pull the handle which releases the slider then move slowly backward to close the gap or forward to open it. While going backward you want to avoid hearing the sickening crunch of breaking plastic if possible or new rear light lenses will be required. If you can’t get under the trailer, because the wheel is in the wrong position and you will hit the landing legs before biting the pin, you pull the release handle then stand on the catwalk and kick [zb] out of the wheel and hope it slides back.
If you don’t fancy the kicking option you can go lower the suspension, go partway under the trailer and lift the suspension until the plate touches the trailer, don’t go too high so you lift the legs a long way off the ground. Then pull slowly forward and the weight of the trailer on the plate should make it move enough before you pop out from underneath and drop the trailer with a loud bang, hence why you don’t lift it too high.
Pop the trailer brake button on, release 5th wheel, then move in either direction?
Yeah, I forgot to put the trailer brake bit. 
But you have to be able to get under it first for that to work. If you are going to hit the legs with the rear of the unit before biting the pin you need another option.
Coffeeholic:
But you have to be able to get under it first for that to work. If you are going to hit the legs with the rear of the unit before biting the pin you need another option.
Like the simple one of using a different trailer, even one belonging to someone else, with a less deep pin as an anchor to move your 5th wheel.
Very unlikely to move by kicking it as probably hasnt been moved or greased in years.
Always try to get somebody to watch what’s happening as you move to watch the lights situation as mention and to pop the handle in when you get where you want it.
IMPORTANT: If doing it alone, when you get it to where you want it, pop the handle in then you must move it again until the locking paul engages between the teeth.
Climb up on the back with no trailer on & have a look at how that works.
Driveroneuk:
Coffeeholic:
But you have to be able to get under it first for that to work. If you are going to hit the legs with the rear of the unit before biting the pin you need another option.Like the simple one of using a different trailer, even one belonging to someone else, with a less deep pin as an anchor to move your 5th wheel.
Very unlikely to move by kicking it as probably hasnt been moved or greased in years.
I’ve moved a few over the years by kicking them but I take your pont it won’t work if it hasn’t been maintained, I did say it might not work.
I saw a mate do it once and he wasn’t really expecting it to move. It shot forward very easily and he fell forward onto the wheel, now that was messy. I couldn’t assist him for laughing. 
In theory you should allow a gap of approx 550mm between the cab and the front of the trailer. you will normally have different kingpin positions varying from 1200mm to 1600mm. A fixed 5th wheel normally set for the 1600mm position so if you hang a 1200mm kingpinned trailer on you would be over length and probably overweight on your drive axle.
I would always use my fore arm as a guide but don’t just check the back of cab measurement also use it to measure rear lights to legs clearence. Our boss always had air operated sliders fitted so we always used them.
The example picture shown with the Merc pulling the racing trailer really shows how not to do it.
http://datasheets.volvotrucks.com/getfile.aspx?id=1024030
Stupot:
The example picture shown with the Merc pulling the racing trailer really shows how not to do it.
It was a bit further back than it need be but this why:
I was on my own, no one around to help as it was lunch time. Been on a steel strapping course that morning & everyone else had got away whilst I was on break eating my lunch.
Initially couldn’t get hold of the pin before the chassis was going to foul the trailer.
Had to go back to another yard to use a trailer as an anchor to move the 5th wheel that hadn’t been moved in years.
The release handle would not stay pulled out.
Waited until another driver (not one of our own) showed up & got him to hold the handle out whilst i moved the truck - watching his toes!
Went back to the race trailer & once coupled up was in position as seen.
If the handle would have stayed out, I would have closed the gap a bit, but I had no way to do that alone.
Weight was not an issue.
Driveroneuk:
Stupot:
The example picture shown with the Merc pulling the racing trailer really shows how not to do it.It was a bit further back than it need be but this why:
I was on my own, no one around to help as it was lunch time. Been on a steel strapping course that morning & everyone else had got away whilst I was on break eating my lunch.
Initially couldn’t get hold of the pin before the chassis was going to foul the trailer.
Had to go back to another yard to use a trailer as an anchor to move the 5th wheel that hadn’t been moved in years.
The release handle would not stay pulled out.
Waited until another driver (not one of our own) showed up & got him to hold the handle out whilst i moved the truck - watching his toes!
Went back to the race trailer & once coupled up was in position as seen.
If the handle would have stayed out, I would have closed the gap a bit, but I had no way to do that alone.Weight was not an issue.
Hi Driveroneuk
I didn’t mean to have a go at all and hope you didn’t take what I said the wrong way.
You see many units driving around with the fifth wheel in the wrong place especially container boys. Someone said about crane drivers swing boxes around into the backs of cabs etc.
I think the main problem is like you said they don’t get moved enough and when you need them they don’t work
Coffeeholic:
I saw a mate do it once and he wasn’t really expecting it to move. It shot forward very easily and he fell forward onto the wheel, now that was messy. I couldn’t assist him for laughing.
I have mine set about 2/3 of the way forwards, I find that with it there I have enough room to get inbetween unit and trailer, and the back of the unit does not seem to bounce as much as it does with the 5th wheel all the way back.