COUPLING? Beware.*

I coupled to an empty trailer, the other day it didn’t sound right even after more attempts. So I tried the forward shunt twice, all good.

I went to connect the dogclip and it would not go in because the Kingpin handle was covering the hole…?!. That’s a dodgy signal. So, I looked at the Kingpin in the 5th wheel (which is why you always apply the handbrake and trailer brake always like your instructor showed you) and the guard had not gone behind the Kingpin.
…which I guess it meant it wasnt engaged properly…!

So I got back in the cab and lowered the suspension a tad (because I go in low then raise it high) and pulled forward an inch and then reversed it back with a bit more conviction and it clanged into place.

The guard over the Kingpin had fully engaged and the dogclip went in the hole.

Had I have forgot the Dogclip it would have been a catastrophe.

It sounds like you probably had the trailer lifted too high, raising the trailer too high can cause the pin not to be locked into position correctly, if you raise the trailer until the legs are just off the ground then reverse slowly until the 5th wheel mechanism clicks into place (clicks not clangs) you shouldn’t have any problems.

There’s no point lifting the trailer any higher than necessary, it doesn’t achieve anything and as you now know it can cause you problems.