Advice for Part #x487c01

Hello there you fine fellow L-gauge enthusiasts. I'm looking for some advice. In my collection I have quite a few old 60s wagon bases (Bricklink part no. x487c01), as pictured. Due to either age or just the way they are designed, there is a lot of friction between the axles and the plastic, and as such they are extremely hard for pretty much any of my locos to pull more than two or three of. Any of you have any experience or advice on what I could try to combat this? Lubricant? Method to...