G920 Steering wheel shaking back and forth

When only driving in my modified Gravil D-series at almost all speeds (going in a straight line) i let go of my steering wheel it shakes back and forth. It is similar to a jeep's death wobble but the shaking is a lot slower. Is this a result from my tuning setup like caster or something?

P.S. I have no clue when is comes to suspension tuning

 

Was this on level ground wheels straight?

Usually your toe should be pretty close to same on both side, but to reduce veering off to side there could be slight adjustment to one or other side, you have toe completely opposite.

Camber looks really odd too, -3.6 is usually what dedicated track cars run, while other side is something one would except from live axle.

That level of caster is found in European sporty passenger cars, as well as race cars, you will get lot more FFB strenght, your wheel might be clipping and if you have not checked 'reduce ffb at low speed' option, there is going to be shaking, but also over 9 degrees of caster is about to make suspension close to fail if not built specifically for that.

Well that is if your vehicle is on perfectly level ground where it is that alignment should be checked and steering wheel dead straight.

Here are educational pages:
https://www.pirate4x4.com/tech/

At least this you need to examine carefully:
https://www.pirate4x4.com/tech/billavista/coilovers/Part_1/

These should help to understand all those angles bit better:
https://www.hotrod.com/articles/ctrp-0801-caster-camber-settings/
https://www.hotrod.com/articles/ccrp-0910-diy-alignment-guide/

Basically anything from realworld works pretty well, things like hydros are of course greatly simplified, but realworld stuff applies to sim too, some bits you can skip and get in those aspects that are valid. There probably are lot of videos on youtube also that explain these and even some sim racing setup tutorials too, which may or may not apply, those can have sometimes things pretty much off.

So lot of studying and research is needed, but it is worth at the end

 

Thank you for the help! Truck now drives great after I read those links gave it a tune.