The wheels on kb keep on shaking when ever I seem to accelerate and I don't know why?
You probably need to balance them, have a look at this:
The main problem you will encounter is that your car is 4WD so you will not have a free spinning axle, you will probably have to remove a drive shaft.
As for the best material to use for balancing, I find that Blu-Tack works great.
It more like the knuckle that's shaking
If you have had a wreck these clips might have came out or broke. Happend to me.
The knuckles still have the clip
Same thing happened with my ken block vxl make sure when u tighten the bolts on the rim to the hex on the axle or else you'll lose the tires in a spin.