now the plastic ring gear on the diffs ive had good luck on personally. id rather run that then the steel one for the lower rotational mass and smoother driveline.
traxxas steel gears are pretty poor quality across the board imo, they are cast gears and its not to hard to miss either, lots of flashing and porous spots, not very smooth. if you take a dremal to it, bevel the edges, lightly sand and polish the gears and use the right grease you can atleast get them halfway decent.
Florida D.O. Racer | Vintage traxxas collector
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