Amp MT diff noise?

[Lephturn]

Relatively new Amp MT is making a noise each revolution. Seems like a click or scrape. Pulled the wheels off and then the cover over the ring and slipper clutch. Pinion and ring gear look fine. Motor is not making the noise. With motor stopped if I turn one wheel and the other turns I don’t hear or feel anything. When both wheels turn the same way I hear it. Seems like something in the gearbox between the ring gear and the teeth on the diff.

Any suggestions? Looks like I have a bigger tear down job to get this all apart.
Since I have the motor off this might be a good time to look at a bigger one. I don’t want to go brushless yet but maybe I need to look at metal gears?

How tight should the pinion be against the ring gear?

 

[Lephturn]

Ok so it wasn’t the diff. Closer inspection with better light revealed a few folded teeth on the spur gear. Oops. Bought two new spur gears.

Now why is it that all of the bearings in the transmission on the ECX Amp are sealed except the two on the output shafts of the diff? The others have black rubber or plastic on the sides to seal them but those two on the output shaft do not. Those are the two that need it the most.

I can grease them but dust will get in the grease and then bad things happen. Seems silly. I didn’t buy the metal gear set but I will look at replacing those two bearings.

 

[Lephturn]

They hobby shop had a new spur gear. But not the slipper clutch pads I need to actually use it. D’oh.