Thanks RCDAD, RCGASSER and CLAUDE BIGELOW.

As for the recommendations/suggestions of all the good peeps here;
I also changed diff fluid, greased all bearings, placed loctite on all metal to metal, installed metal servo arm, changed some screws using rcscrewz.
I accidentally stripped the set screw of one of the wheel adapters and of course... WHOOOA! you gave me the answers how to take it off.
Hopefully it starts when I decide to start it up and the kill switch doesn't give me issues. But then again... no worries 'cause I know the good fellows here will give me nice support/answers.