Old email from a friend who used to be cabinet installer /builder after I had some break...
Why didn't you mention your RV was using those things? I used to throw them way and used a piece of wood to hold the drawer slide in the correct place. They are only for adjusting the drawer slide from side to side. Reroute by here and I will fix your drawer slides so they don't break and they work right. and make a list of everything else that needs to be fixed!
He fixed mine by replacing all ot the plastic spacers and they are so much better