@DTGREENLANER I'd say that's a dry bearing inside the servo somewhere, I think they can be taken apart and the gear train serviced. Never done one myself but it's pretty much a scaled-up RC car servo, just take your time and lay everything out in the order you removed it and you should be all good. Southeast Asia is full of DTRs, DT230 Lanzas etc. and some of those guys repair the servos quite often.