4) Main Landing Gear Down-Lock Wear

(1541038-1, -2 and 1541006-2)

Over the many years of Skymaster operation the main landing gear down-lock stops, stop pads and down-lock pin/chrome ball can become grooved, dented or worn. As the landing gear is extended, the chrome ball/ pin assembly p/n 1541006-1, -2 ,-3 rides up and over the down-lock stop assembly p/n 1541038-1, -2 and the downward movement of the gear leg is stopped when the chrome ball impacts the stop pad. We have seen many Skymaster aircraft with groves and wear on the down-lock stops and stop pads and even seen ones that are mangled/missing as well as excessive wear on the chrome ball. The problem is with this type wear there can be excessive up and down movement of the landing gear legs and possibly cause down-lock damage or other main landing gear parts damage, therefore it should be checked each annual inspection. Cessna Service manuals shows that the clearance between the chrome ball and the down-lock stop be snug to .005 inch or less. With the aircraft on jacks, if you can lift the main gear leg up and down and observe movement, there is too much play/movement.

First remove and replace worn parts, then the adjustment is a trial and error process. See Cessna Service Manuals. Remove the cotter pin and nut (AN32-6) and bolt (AN26-20) holding the chrome ball and block assembly then increase/decreased the length/height of the ball by “one flat” per try. Reinstall the chrome ball and block and recheck for main gear up and down movement. Repeat as necessary.

We found the best way to bond the down-lock to the main gear strut leg is to apply “JB Weld” between the inside of the down-lock assembly and the gear leg. The down-lock assembly is positioned by one of the bolts holding the saddle clamp (p/n 1512247-2) over the top of the gear leg. Commodore Aerospace Corp have all these main landing gear parts in stock.