Look for a credible mating pattern

A mark whose shape or position corresponds to another part can be more informative than an isolated shiny patch. Existing images may show paint transfer, a repeated arc or a boundary aligned with possible motion. Do not move the cover or rotate a mechanism to obtain a matching mark. The examination must account for actual machine state and safe access, rather than reproduce contact informally.

Distinguish static fit from operating clearance

A stopped assembly can have clearance while movement, deflection or thermal change brings parts into contact in another permitted state. The engineer needs the actual geometry and relevant movement envelope. A static gap photograph therefore cannot settle the rubbing question. Conversely, a fresh-looking mark does not prove ongoing contact if handling or prior work provides another plausible source.

If the apparent mating part also shows a corresponding fresh mark, that strengthens a contact hypothesis but does not establish the operating condition that caused it. The engineer still needs to consider movement, support condition and any changed assembly geometry before selecting a correction.

Ask for condition and cause together

The review should establish whether the surface has lost protection or material and why contact occurred if it is confirmed. Repainting the shiny region without resolving interference can conceal recurrence. Bending a cover or adding a spacer is a design change requiring the appropriate evidence. No MARSTON cover clearance, deflection allowance or acceptable rubbing condition is asserted here; request the component-specific assessment and correction.