1960's Sliding glass door roller replacement

Dear Swisco,

I have a client that is on a very fixed income. I occasionally do work complementary for them. Her patio door has been repeatedly coming of the lower track making it almost impossible for her to open it. She has outside burglar bars installed on the outside.

 The rollers that are installed on the doors had no adjustments that I could get to to allow for clearance. I didn't have enough room to get the door to clear the inside of the tile, trust me I tried. lol. I eventually disassembled the door. It's the kind with the frame and gasket that just unscrews. Okay, to get to the point I would like replacement rollers (4) that are adjustable to allow clearance without having to put back together while in the groove. Below is a photograph of the existing roller.

 Once I had the door out, I was able to loosen the two screws and gently tap the unit out. Any assistance would be greatly appreciated.

Thanks, Rock

Thank you for the information. I did end up replacing the units with slide in adjustable rollers. It would have been nice to locate new glass seals and such, but none available locally. Everything works as it should with a just a slight touch of a finger. Thanks for your time and may you and your family be blessed.