Can you measure the bushing and hinge diameters.
Are you buying genuine ones?I've had no luck finding good replacements either. The original ones (that were cracked when I got the truck), were the only ones I've received that had a wide enough slot. Every other pair since I've had to widen the slot in the bushing by a couple millimetres. Every other set has also cracked... well except the ones I put in a week ago...