I'm wondering If the gear mesh is a little loose . Yea put the alum case on . I have that on mine . The plastic may be flexing just enough under load to tear them up . Worse case you could lock em up
Turn a solid spool on your lathe ? to put the ring gear on . Looks like you got enough weight and length it shouldn't effect steering to much . + you wont get stuck unless you spin all 4
