On 14 Jun 2017 17:44:48 GMT, notbob wrote:

On 2017-06-14, wrote:

Exactly You need to remove the door, clean and lightly lubricate the
wheel bearings.

Bearings? You are making the assumption his sliding door even has
bearings.

I suspect many doors, out there, are as cheap as mine. No bearings
and the wheel adj blocks are shot (stripped threads in the cheapo alum
adj blocks). You may be better off replacing sed sliding door with a
better one, though it's gonna cost you! I hadda take a 4-1/2"
right-angle grinder and open up the frame to allow the near-broken
wheel adj blocks to allow the wheels to even engage the floor rails.

I'll be replacing it, eventually. Sad! 8|

nb

There is some kind of bearing in there. A better door will have ball
bearings, cheap ones use oilite bronze bearings.
YMMV on lubricating them but usually something like 3 in 1 oil will
work for a while.
Usually you can find the whole wheel assembly at a good door shop and
the more popular ones are at Ace.