The pilot reported that he made a short field approach to the 080 degree strip in a 10 knot easterly wind. He said that on short final approach some sink was encountered which resulted in the aircraft touching down short of the threshold. The pilot believed that touchdown was normal for a short field approach but the wheel marks on the strip suggested that it may have been heavy. When the aircraft touched down, the right main gear tracking arm (P/N 105-810021-4) broke. This resulted in the wheel assembly detaching. The aircraft skidded to a stop after rotating to the right through about 170 degrees. The broken tracking arm was subjected to microscopic examination which determined that it had failed due to overload. There was no evidence of any fatigue or pre-existing damage. In addition, the damage to the wings was also consistent with a heavy landing.