Lower Arm making contact with knuckle…

[GranPrix]

Have you tried the wheels turned to maybe 1/2 to 3/4 of their travel, holding the brake really firmly and goosing the throttle? Try it in forward and reverse and with the wheels turned both directions.

Tried it yesterday and nothing

 

[iamdub]

Tried it yesterday and nothing

This is good. That would put a lot of shifting weight on the arms and bushings. If they didn't make the noise when doing this, then they're likely not the source.