I have 2 servoes in the ailerones that have the jitters and will not center. Have tried everthing from frerite cores to wrapping wires.I have 5 in plane and the others are fine.It is in a sukhoi su-31 gaser.The servoes are Mpi`s Mx-450Mg Hp-Hi-torque servoes.I have tried different servos in reciever and were fine.Did I pick 2 bad servoes for the ailerones or what?

Try stepping a few feet away with the transmitter. Often, a close proximity of Tx and Rx will cause servo chatter.

Are you useing a 6v Rx pack?

Do they do it when the engine is not running?