Sorry if this is in the wrong section,I couldn’t think where to put it.
Is it possible to reposition the kingpin on a 2006 trailer? The reason I ask is I have been asked to move a stepframe that has king pin at 1900mm and doesn’t leave much room or options for the tractor unit.if the pin was at 1500mm it would mean it could be moved with any no. of units. Would it be a big job to move the pin. I’m fairly sure I heard before that trailers had options of where the pin sits but can’t find any info anywhere.
Usually the pin will be part of the integral design of the trailer and would (normally) have to either go back to the manufacturer or a trailer specialist to be modified. Theres probably specialist type trailers out there with moveable pins somewhere but most will be fixed. Most shorter wheel base units will have a sliding fifth wheel to compensate. We all use long wheelbase 4x2’s which are all capable of deep pin trailers for close coupling but we have had in the yard in the past the odd Uk spec swb with fixed fifth wheel not capable of pulling our tilts…
Daft one, have you looked at the bed plate to see if there’s another set of mounting holes for the king pin.
Only saying as some of our clients 1998 vintage skellys have this.
Thanks both of you .Andrew that’s interesting about the lwb 4x2’s . There is one 4x2 lwb with slider but there might be a crane going on behind the cab.which would leave about 1800 mm between crane and 5th wheel I think.about 100 mm out the wrong way.
I had a look at the underside of the trailer but good point Phil. Do you think there is a chance of a 2nd pin fitting point accessed from the top of the trailer bed?
All the Best
You can’t move the king pin, you have to move the fith wheel.
You might find there are two possible mounting positions for the kingpin, most of the early 13,6m trailers had two mounting positions to allow coupling to older shorter wheelbase units.
It’s a horrible dirty job to swap them around and you are guaranteed to get grease in your hair.
newmercman:
You might find there are two possible mounting positions for the kingpin, most of the early 13,6m trailers had two mounting positions to allow coupling to older shorter wheelbase units.It’s a horrible dirty job to swap them around and you are guaranteed to get grease in your hair.
True enough with trailers from the time when we went off 32tons on 4 axles to 38tons on 5 axles. The company I was with then had one trailer where the king pin could be swopped by removing about a dozen bolts and another two or three fitted with a very elegantly designed bit of kit: the trailers had two pins, either of which could be folded up flush into the rubbing plate, and were secured by spring clips released by a heavy flat bladed screw-driver. Just a 2 minute job to drop one and tuck up the other. Ran them for years too with no play apparent in the pins.
I’ve heard of those dual pin trailers, but never seen one. I know about the dual position thing through bitter experience, I got a tug at Beattock and had a long pin trailer and a short wheelbase unit, so had the 5th wheel right back to avoid mangling the back of the cab, needless to say I was over on the drive axle (and gross, but that’s another story) I couldn’t move the load as it was a floor load of HobNobs floor to ceiling right to the back doors, a 6 wheeler unit wasn’t an option as A, it would be even more over gross and B, we didn’t have any, so I had to move the pin and get some of the weight off the drive axle.
I was completely covered in grease by the time I finished and still overweight, but they let me go on my way (I was taking it to Gibraltar) and I never heard anything further about it, which was a proper result, the firm would’ve paid the fine, but it would still have been on my record with the traffic commissioner.
newmercman:
I’ve heard of those dual pin trailers, but never seen one. I know about the dual position thing through bitter experience, I got a tug at Beattock and had a long pin trailer and a short wheelbase unit, so had the 5th wheel right back to avoid mangling the back of the cab, needless to say I was over on the drive axle (and gross, but that’s another story) I couldn’t move the load as it was a floor load of HobNobs floor to ceiling right to the back doors, a 6 wheeler unit wasn’t an option as A, it would be even more over gross and B, we didn’t have any, so I had to move the pin and get some of the weight off the drive axle.I was completely covered in grease by the time I finished and still overweight, but they let me go on my way (I was taking it to Gibraltar) and I never heard anything further about it, which was a proper result, the firm would’ve paid the fine, but it would still have been on my record with the traffic commissioner.
Good result as you say!
The company that had those trailers were running a mixed fleet of 2 plus 2 at 32 tons, 3 plus 2 at 38 tons, and 2 plus 3 at 38 tons. The drop pins were on spread axle trailers so they could be used by both 2 axle units at 32 tons or 3 axle units at 38 tons. 44 tons on 6 axles meant no further need for complications of course. The pins seemed to be machined from a solid block of high quality steel on a solid square base. The square base was a very snug fit into the rubbing plate recess, and when not needed folded up sideways into the plate. Worked well for years.
I seem to remember there was a rule whereby you could run at 36 ton on 4 axles if on an international trip? Or was another one my boss got away with? 
Some of the older tilts we use from Hungary have been modified no end. Theyre ex Norfolk line pre 13.6m VanHools which have been totally stripped, chassis extended to 13.6, axles repositioned and long pins for close coupling. The tilt covers have even been extended by bonding extra material from scrap ones.A real mish mash but labour costs being what they are there must be cost effective…
daesal:
Thanks both of you .Andrew that’s interesting about the lwb 4x2’s . There is one 4x2 lwb with slider but there might be a crane going on behind the cab.which would leave about 1800 mm between crane and 5th wheel I think.about 100 mm out the wrong way.
I had a look at the underside of the trailer but good point Phil. Do you think there is a chance of a 2nd pin fitting point accessed from the top of the trailer bed?
All the Best
I have never heard of a trailer with a 1.9m pin it is impossible to couple to legally; don’t forget that the measurement which matters is from pin to the trailer corner, if it has square corners that will be close to 2.4., 2.3ish if it has cut of corners like a curtainsider. I dont believe that the unit exists that can have the 5th wheel so far back and remain under 16.5m overall and if it was a 4x2 you would definitely risk a serious drive axle overload. Unless it’s a very short trailer in which case off you go, but still weird.
Moving the pin is possible, but as has been said it’s a big job and would be a notifyable alteration requiring a visit to a test station.
I think it was 35tons on four, with road friendly suspension, but the tax on such a configuration was a fortune.
newmercman:
I think it was 35tons on four, with road friendly suspension, but the tax on such a configuration was a fortune.
Ex TIP Rental chassis-less alloy boxes running on tandems with steel springs probably didn`t really qualify then? They did a lot of good work after their rental days were over, but the bodies did creak somewhat alarmingly with loaded forklifts driving inside them. All a long time ago now.
As said before, check under the trailer to make sure there isn’t already a retainer plate fitted in a shorter position. If there isn’t, you would have to pull the floor up over the rubbing plate area and see where the crossmembers are. It is perfectly feasible to cut a hole in the rubbing plate, weld in a new retainer plate then bolt a new kingpin into place but you would have to know what you were doing and would probably have to weld in additional crossmembers. Bear in mind also that if it’s a 2006 trailer it will have some amount of wear on the rubbing plate already, so it may be worthwhile replacing the rubbing plate complete and fit the kingpin in the desired place. As stated before if you change the position of the kingpin you may have to submit a notifiable alteration. To replace a rubbing plate budget in the region of £2000 to £2500.