Source: 2005 Q3 Beartracks
In the service bulletin concerning the replacement of the rod end bearings it was mentioned that the landing gear geometry must be such at the tread is 72” (measured center of wheel to center of wheel) when at normal weight and maximum 74” at gross. These dimensions are critical because the loads on landing gear components increase dramatically as the wheels are allowed to splay out. They absolutely must be held.
To check the spread, you can load the airplane then roll it forward and back, giving the gear time to equalize. Another method is to take two pieces of old Formica counter top, place them face-to-face with grease between them. Then this homemade “slip plate” is put under one wheel and the airplane rocked by the wing tip a few times until everything settles out.
DO NOT UNDERESTIMATE THE IMPORTANCE OF KEEPING THE GEAR TREAD WITHIN THESE LIMITS. ALSO REMEMBER THAT THE ONLY ACCEPTABLE ROD END BEARING FOR THE SHOCK STRUT IS THE AURORA XAM-7M. This magnafluxed bearing can be purchased from AviPro.