It is very unusual for oem bushings to fail so quickly.
As the centre of the bushings are off centre they do have to be pressed into the compression rod in a fixed position for caster tollerences.
If this has not been done correctly then extra load may be placed on the bushings causing premature failure
Also:
The maximum force to remove the old bushings must not exceed 4,49 tons.
The maximum force to fit the new bushing must not exceed 3,93 tons.
And finally a force of 1.12 ton should be applied to the new bushing (once fitted) as a test to confirm that it is tight enough in the compression rod.
If any of these 3 tollerences are negative, then new compression rods should be fitted.
PM on its way with more info:
Alex.