Foward Motor mount reinforcement
Posted: Tue Dec 26, 2023 5:46 pm
I recently had a motor mount fail in several areas due to a violent nosewheel shimmy caused by a collapsed strut . I purchased a new mount and added reinforcement according to the Lancair SB. I've noticed on several ES aircraft including mine the forward mount attach metal donuts had a tendency to expand from the left donut to the right donut. This is quite evident from the elliptical pattern of the lord mounts instead of being concentric as they are on the rear mounts. Id be interested to hear from other owners if they have expanded forward mounts. I'm not sure if the Legacys, 360s, and 4s have the same mount configurations? if they do I'm sure the same problem could be evident.
It appears the bracket bolted to the engine is preventing the mount from expanding to failure and cracking however, I believe its putting a serious sideload on the engine mount itself. If you look at the rear of the engine mount there is a lateral tube running left to right reinforcing the rear donuts however there is nothing on the front. I believe there is a design flaw, and the front needs to be reinforced as the rear is. I'm currently making modifications on the front mount and will send pictures when its completed.
It appears the bracket bolted to the engine is preventing the mount from expanding to failure and cracking however, I believe its putting a serious sideload on the engine mount itself. If you look at the rear of the engine mount there is a lateral tube running left to right reinforcing the rear donuts however there is nothing on the front. I believe there is a design flaw, and the front needs to be reinforced as the rear is. I'm currently making modifications on the front mount and will send pictures when its completed.