housing sits straight until our fr5 fingers close

Same retained housing twists in two pockets. Photos show one finger touching first, not why yet.

One contact first is worth following. Show the fitted pads against the drawing before calling it arm drift. Another pickup correction could make that crooked contact look less obvious without fixing it.

Were the pads issued as a pair?

Our spare pad once had the correct face but a different backing thickness. It came from another repair. The part number on its bag looked reassuring until we measured the assembly.

Marcus, was the difference on the drawing or only on the thing in your hand? I ask because a wrong drawing can produce a very convincing inspection result.

Stores found separate issue dates. Maintenance has taken the pad assemblies for comparison; lesson postponed.

Compare the mounting faces too. The pad thickness alone won't tell you where its working face ends up.

It was on the earlier repair drawing, Jamie. We had compared the loose contact face with the current drawing and missed the backing. Our mistake was choosing too small a piece to compare.

And my tray suggestion still needs checking, but Gavin has a better lead now. No point defending a guess just because I posted it first.

Found it. Replacement pad has a taller backing than this tool drawing permits. Tray contacts checked out.

Is the replacement pair actually in stores?

Yes, checked pair fitted by maintenance. The retained housing now closes square in both pockets.

Thanks Rosa. Checking what we owned saved another speculative pad order.

Have maintenance reconcile those saved pickup corrections before the teaching job goes back into use