Servo issues

[AfroP]

hi guys

bit of newbie question here, hopefully somebody can help.
have just finished with my 22 build and have a savox 1258 installed(yep its all mighty tight)
Have brand spanking new DX2 transmiter so everything is default.
my problem is that my car turns left more than it turns right and the servo seems to whine constantly.
If I adjust the trim slightly it makes the whine go away for a bit but as soon as I steer it starts up again. I've read that this is common with digital servo's so not that bothered by this.
My main issue is getting my left and right turning circles to be the same.

any advice would be greatly appreciated.

cheers