It is known that over time a regular door and other hinges start to creak, and lubricate them from the inside is not so simple: sometimes you have to remove them, which is not always possible.
However, once you drill into the top level loop through hole to the axis, and lubrication is simplified, and the result is excellent: the loop will stop squeaking for a long time.
Recommend to read
PETLYAKOV PE-2
Dive bomber PE-2 was developed in OKB V. M. Petlyakov on the basis of previously established experimental twin-engined high-altitude fighter VI-100. The first production PE-2 was...
STEARMAN PT-13/PT-17/PT-18
In 1933, the designers of the American company "Starman" designed the training aircraft, with a motor 215 l,p, called the "model 70". It was an all-metal biplane with fabric covering,...