Hi Blue Albatross,
Used to look after one of these a few years ago. It had all the problems the ATL's suffer from, including your problem. May I suggest that you check the tracking of your mainwheels. Easiest way is probably in a hangar. Lay a piece of string or similar along the floor of the hangar aligned underneath the fuselage precisely along the centreline of the aircraft. Note: from the centre of the tailcone forward to the middle of the bulkhead/firewall - don't try and align the string from the tailcone to the spinner as these engines have considerable offset. Then align a straight edge (long piece of wood etc) fore and aft along the outside of each mainwheel. Now measure from the distance from the wood to the string both at the wheel, and then from approximately 10 feet/3 meters forward of the wheels. These distances should be equal (i.e. the wood runs parallel to the string). I suspect that your port wheel is toeing out.
Hope this helps.
camlobe