727-100  GW 161,000 Lbs and my test flight TOW 135000Lbs. You cannot put  28500Lbs into three Stations. You have the distribute the weight to each available stations,
If you look at Default 737-800, its   easily  distribute 28,500lbs  to 9 stations  and front wheel will not sunk.

727-100 aircraft,cfg file you will see  available stations are 50. but CS only activated 3. That is the problem.