slipping for no reason

[truckstuff]

i have 1/10 ECX Ruckus i locked the slipper down as much as possible, the top shaft is spinning but the wheels are not so the problem must be in the gearbox somewhere, the problem with that is i got the new gear set and replaced all the gears even the ones inside the diff, off the ground with no load works fine on the ground its slow and seems like the slipper is slipping, but the slipper is not slipping what could possibly cause this?

 

[i_r_beej]

Does the transmission make a buzzing noise (like teeth on one of the gears has stripped)? When you run the car with wheels off the ground, what happens when you grab only one of the wheels (to stop it turning)? Does the other wheel spin? Wondering if maybe something is up with the differential assembly.

Hm. Check the two metal pressure plates in the slipper assembly. They have flat sections that "key" them to the top shaft. Are they rounded out? Is the top shaft grooved? I'm wondering if something has happened to the pressure plates or top shaft.

 

[Jerry-Rigged]

also, hold the truck, give it power (light throttle, not WOT), and see what is spinning and what is not - go down the line. Is the pinion spinning? Spur? Is the slipper shaft spinning? One or Both diff outdrives? If one outdrive is spinning, you probably stripped a wheel hex. If both are spinning, you probably forgot the crosspin behind the hexes... (Ask me how I know LOL )