I was told over 30 years ago by a knitting machine engineer that you should never use WD40 on any knitting machine or ribber.
The same engineer told me, just in time, that under no circumstances should you ever use silicone spray to lubricate a knitting machine, as the silicone dries creating a coating on all of the metal parts which is very difficult to remove. As the spray also ends up inside the needlebed, it is very costly to have the machine stripped down completely to remove it.
He also believed it was not wise to spray silicone spray on the yarn you are knitting with, as it would still end up coating the needles.
I had sprayed my machine a few times before he gave me that advice, and my carriage had become extremely heavy to punch across the needlebed. Fortunately I was still able to get it cleaned off quite easily. I never used it again!