What are the purpose of kiln movement uphill/downhill?

The purpose of kiln movement is to get equal wear in tires and rollers. Rollers should be adjusted to “float” the kiln between the upper and lower thrust rollers. The gap between Thrust rollers and tire is 1/4". The total amount is  1/2".
When rollers are misaligned or conical-shaped, the kiln load is spread over too small an area. This causes high surface stresses resulting in pitting.

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