We have an 07 Diplomat and we had problems with our bedroom slide.
It turned out that the bearings, which are located under the bed, was completely crushed. You can lift the bed and remove the plywood sheet in the bed cavity to check on this. We contacted the slide-out fabricator (the name escapes me for now and I can't go check since I am 5000 miles away from our MH) and they shipped out new bearing to me since we was still under their warranty.
The replacement job was not to difficult at all but as usual I did panic before finding this out

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I do recognise the problem MM is referring to about the underside of the slide-out being damaged and this is something I will have to address shortly.