Originally Posted by Chris Nicastro

When you look at the top of the wing, gear down, tail on the ground (then tail raised level) you will notice where the axle is relative to the leading edge of the wing. The best position for the axle is to be well forward of the LE when the tail in down and at least even with the LE when the tail is up. This keeps the mass of the plane behind the axle as much as possible to help make it stable. As the axle position moves back the condition gets worse and all the typical problems get worse, nosing over, erratic veering, etc.
Look from the top the side views to get measurements and impressions on what's going on.
Adding a spacer to the back edge of the retract works but pay attention to the retracted position of the wheel too. The struts are like a foot long so a small washer under each screw is a good start then add two and see how it goes.

I usually set the gear/wheel at least parallel to the center line of the plane and then see how much deflection or twist there is in the strut. If the strut it tight then I add more toe out. If the strut is loose then I leave it because the torque of the wheel on the axle and lower leg will be enough of a toe out angle. You're looking at the scissor link for this info.

Also, it should be considered to replace the springs in the Robostruts with softer springs or a dual rate spring. They are made with very stiff springs! Its better to have a dual stage set up common on Yellow AC retracts. Ive made this mod to my planes many times and its so much better than stock.