Hi, I juz bought a HS-6985HB for my truck as steering servo. Upon testing the servo mabe a very loud something like electric sound when its on load. upon lifting it off load the sound disappeared. but after steering again the loud sound came back. Is this normal for this particular servo???

What your hearing is the digital circuitry. All digitals make noise like that when they are under load. Its normal.

Thanks for the fast reply... I do own another Hitec servo HS-5945MG. It does have a digital sound but as compare to the HS-6985HB servo the sound is really loud; abit irritating, but it still works graet though...