Before I got my 16k Reese fifth wheel hitch, I saw somewhere on the internet a caution against lubing the king pin of your trailer and where it locks to the hitch, hitch part. The reasoning was that friction is important to the nature of the hitch, and lube there was a no no. I don't see that same precaution in the Reese papers or my fifth wheel manual, but they are kinda vague on it. I got a Reese nylon lube "wheel" on the fifth wheel, and need feedback on lube on the kingpin. Comments?