FWIW: I have a Jack Knight Rack on My +8 Bitsa. Steering got sloppy. There is a block of Nylatron that pushes the Pinion into the rack. It had swelled. I was able to get the Nylatron out but could not get it back in. A Machinist Friend used a lathe file and re-fitted the Nylatron, About 3 years ago. So far so good.