http://www.nitrorcx.com/sava-green-m...net-truck.html
If you look in the specs and special features, you will see "oil serviceable diffs" or diff gears, could be worth looking into
Work because i gotta, play because i wanna
People here hate Nitro, I love it. I start it, run it about 50 ft from me and it dies, I go after it. Perfect exercise