Main gear brackets on my tailwheeled RV14 keep breaking the AN3 bolts that fasten them into the axle. Operating off of grass and a "Navy" landing will hasten the failure. I have had approximately 6 bolts shear right at the head, both sides of the aircraft. So far I have been able to get the stud out with EZ outs, but at some point the threads are going to get out of tolerance. I realize the weakest part is failing (the AN3 bolt) there is not enough material to increase to a AN4 bolt and I am concerned that fixing the weakest link will potentially move the failure to the next weakest link. Right now I have just removed the wheel pants until I can find a better solution. Any ideas?