The bi-fold door lower guide needs to be replaced. the guide is similar to your bifold door cap. Part no. 21-103. The apart I have is 3/8" where the 21-103 is 1/2". Is there barrel of 3/8".
Check out our 21-106 Cap. This has a top with an outer diameter of 3/8", while the hole to accept a pin is 3/16" in diameter. Let me know if this matches.
