New Rustler weird issue

[rwordenjr]

Just got this new rustler and installed the 28t pinion and 86 spur gear right away so I don’t know if this is the reason for this but the left rear wheel moves before the right wheel. I’m sure this isn’t an issue brand specific but any ideas ?

[tamiya3speed]

Try to isolate the side that starts stationary.  Double check hubs, driveshafts, wheel attachment for any signs of binding or interference.  Check diff for grittiness, seems like something is binding though.  If you pull the pinion you should be able to spin everything more freely.

[markbt73]

I can't get your video to play, but knowing what I know about that gearbox, I would look at the gear cover and make sure it's seated properly. There's a cutout in the bottom of it to clear the right side U-joint, and if it's off-kilter a little bit, the gear cover can rub against the U-joint and cause a little drag.

If it's not that, try compressing the rear suspension a little bit and see if it still does it. The right-hand driveshaft might be rubbing on the lower suspension arm. If that's the case, you might want to limit the rear shocks a bit so they don't droop so far.