Hello and welcome to Just answer.com, Super mechanic here. About your vehicle.
See Figures 8 through 12
Jerking the right wheel assembly back and forth is not an acceptable testing procedure; there is no control on the amount of force being applied to the idler arm. Before suspecting idler arm shimmying complaints, check the wheels for imbalance, run-out, force variation and/or road surface irregularities.
Fig. Fig. 8: Checking the idler arm for wear or damage
Fig. Fig. 9: Using a back-up wrench and a ratchet and socket, remove the idler arm-to-frame nuts and bolts
Fig. Fig. 10: Remove the nut from the idler arm ball stud
Fig. Fig. 11: Use a suitable steering linkage to separate the relay rod from idler arm ...
Fig. Fig. 12: ... then remove the idler arm
See Figures 13 through 17
Fig. Fig. 13: Exploded view of the relay rod-2WD model shown
Fig. Fig. 14: Exploded view of the relay rod-4WD model shown
Fig. Fig. 15: Unfasten the relay rod-to-inner tie rod nuts
Fig. Fig. 16: Use a suitable puller to separate the relay rod from the inner tie rod
Fig. Fig. 17: Remove the relay rod from the vehicle