Now CF me old mate, i wasn’t going to get involved in this now you’re on another crusade, but i’m afraid the young lads are doing it right and i agree with Santa that you’re just plain wrong on this one mate…with one small proviso** which i’ll get to later on.
So, to groans of oh hell not again here we go.
The grease situation to which you refer in disparaging terms is actually a very valid one, a freshly serviced tractor might as well not have been serviced at all if you’re going to wipe 2lb of grease straight up the font of the rubbing plate; for one thing soon as you take the first tight turn it gets smeared all over and into the suzies and hydraulic hose (if left attached), and i don’t want to get into the rights and wrongs of hydraulic hoses semi permanently attached because its company procedure on ours.
Secondly, the grease isn’t doing it intended job; some places, such as where i work we have a regular trailer (tank in my case) so once coupled mone might stay connected for three weeks before a slight product variation or route/maintenance planning cause a trailer swap, being a tank the rubbing plate (whilst the king pin is as deep as a normal van/curtain sider) is quite narrow, and unless the service grease gets to where it was intended by the time service comes round again the king pin will be running dry and down to metal to metal in a few spaced arcs.
If i connect it myself and do the job as the lads above suggest the grease won’t be wasted or make a mess and will keep the plate/fifth wheel still well lubed for the full 6 weeks.
Back in the days of proper lorries (sorry lads had to get that one in 
) with gearboxes and ■■■■■■■■■■■■■ etc under your bonnet giving you a decent semi much of the time when in full howl, the trailer king pin depths weren’t so far as they are now, that fresh grease that didn’t get wiped up the front of the rubbing plate didn’t get as much loss as it travelled the generally horter distances to the kin pin area.
Rubbing plates, vary a lot, they are not the huge flat plates you find on vans/curtains; on specialist trailers such as tanks and the now rare (apart from Stobarts short lived revival of circumcised semi trailer car transporters) semi trailer car transporters where the rubbing plate can be not much wider than the fifth wheel and i’ve seen many trailers where the rubbing plate is so narrow that a couple of valuable (Dipper Dave, you’re in here… 
) inches of fifth wheel protrudes either side at all times.
In such cases as these especially but this also applies to all rubbing plate designs they can and do run dry during use so it makes sense to get that nice new grease where the mechanics intended it to go.
How many times have we, i know have experienced that strange sensation of the artic not wanting to tae corners, odd handling indeed even manifesting itself as being difficult to control on a badly worn (grooved) motorway, often enough here we’ve suggested to the complainant to check the fifth wheel cos its probably gone dry, i’ve actually had semi trailer (uncircumcised, with peak) car trasnporters where the fifth wheel has been screeching cos the plate had run bone dry during really wet and salty weather.
That grease needs to get to the rubbing plate.
Then we have the case of rubbing plates with cut outs, some rubbing plates, on tanks again for reasons of chassis build and some weight saving, are not solid from front edge right to the actual main rubbing plate around the king pin, you can find large sections missing if you look underneath (LAG tanks in particular, a very high quality product indeed) if you try to drop a tank with such cut outs without dumping air (so doing it as one would have on steels under full spring pressure) you can find that as the fifth wheel tilts back and the trailer ‘spits you out’ (Dipper Daaaave… ) the pick up ramps can get wedged into those cut outs and in extreme cases have punched holes through the the front of the chassis.
Similarly you imagine the scenario of picking one of these up the old (your) way its not as simple as it looked picking a tank up, its OK when its a regular one for you as you learn how to get it lined up via side light marker bars etc, but when its a different make tractor and trailer it can be a hit and miss affair, requiring several reverse it up close get out and have a look call yourself a plank cos you’re a good 6" out either side (DIIIPPPER DAAAAVE… ), you go pushing back like that and you can soon be in a right pickle.
Then you have the unenviable times you have to pick up such a trailer on the ■■■■ cos you simply don’t have the space to get the tractor unit in a straight line with the trailer, picking one like this up thats been dropped low can be a perilous affair…now you throw the aforesaid rubbing plate cut outs into the mix both for dropping and picking up procedures.
No i’m sorry mate but air suspension has been a Godsend in so many ways** for the dropping and picking up procedures and i have to concede** i’ve had to change my procedures to make the most of it but i’m glad i have.
We’d be idiots not to take advantage of being able to use such a device to make our coupling procedures cleaner, safer and kinder to the vehicles in all ways.
** just for the sake of argument i’m not entirely convinced that an air sprung tractor makes a more stable handling lorry than an steel sprung unit, but thats an argument for another day and not really one for the main forum, more like fodder for the old timers forum.
I’ve had steel sprung tractors that were more comfortable on the road than air sprung too, but i agree that generally its a better system with its versatility.**
Oh and by the way, its isn’t the height difference or not between a fifth wheel and kin pin which causes the false pick ups where the pin ends up on the jaws, it needs uneven ground where the king pin can trigger the jaws closing at a slight angle, the one and only time its happened to me (which thankfully i realised summat wasn’t right, dragged it down, checked and realised the problem so dropped and re-picked it up) was picking up a fully loaded loaded trailer dropped properly low old school steel spring style with a steel sprung tractor.
If you go in flat at the wrong height the jaws can’t lock on because the wider section of the pin isn’t triggering jaw lock properly.
This doesn’t mean to say that anyone should be anything but vigilant at all times and keep you wits about you, cos once its bounced off and caused whatever mayhem it will you can’t reset and go back to start like on a video game.
It took me some time to come to terms with air, didn’t get Santa’s valuable training, and to work out out how to get the best from air suspension when i came back to artics too, if thats any consolation CF old chap.
Here endeth todays waffle… 
