I have a similar question as yours. Just this weekend, my door on my 410 got very sticking and was hard to close. I removed the roller bearing assembly on the bottom left corner and the bearings were ground down and they just fell out of the housing. I am now looking to locate the replacement roller assembly, so any help from folks on that would be great. The disassembly is very easy as you just remove the allen head bolt that goes into the roller assembly and the rollers just slide off the track. I would highly reccomend lubing the bearings going forward as they seem to wear rather quickly.