Cobra Racing all aluminum SEALED differential COMPLETE (we've used hardened steel planetary gears inside) with all the gears and 50k differential oil fluids pre-loaded into it.  These sealed aluminum differentials are hand assembled in the USA, and meet the rigerious Cobra Racing standards.

Installation is super easy.  Just take out your transmission, remove the old differential, and replace it with this one and put the car back together (no need to buy or swap out gears inside, this one is complete).  We chose to put 50k diff oil in these differentials because after vigerous testing, we've found out that 50k weigh limit gives you the best of both worlds (racing and bashing).  

Why diff oil instead of grease?  

With grease, the viscosity is very low, and that causes the differential to slip quiet a bit when you hit the throttle.  This slippage causes the car to lose a lot of traction and power.  Grease is typically equivalent to 10k differential fluid (if we where to do a comparison).  By putting 50k diff fluid in these differentials, we slow down the differential quiet a bit (which in turn causes your car to diff out much less frequently).  By slowing the differential down, you gain a TON more traction and a lot more power / speed.  This is especially important with 2WD cars as they tend to lose control under heavy, or abrupt throttle (which makes them not as fun to drive as 4WD).

Traxxas Slash

Traxxas Rustler

Traxxas Bandit

Traxxas Stampede

1 Aluminum sealed differentials COMPLETE with all gears (planetary gears, output shafts, etc...) with 50K weight differential fluid pre-loaded