someone from the traxxas forum said this to me and it makes sense.
get aluminum cases for your diffs if they are separating and causing your ring gear to strip.
get aluminum cups for your diffs if they are separating from the ring gear and causing your spider gears to strip.
if you strip spider gears with aluminum cups, then the gears are too weak for you and you need to get the 1/8th scale stuff.
that's my opinion.
so after reading that, i decided i should inspect my diff cases since it was my ring gear that got stripped twice and no where else. my spiders are in perfect shape.
and how do you know it, one of the screws of the 4 screws that hold the diff case together was stripped! so i hope that was the cause of my issues because my diff case was just flexing.
so now, i am probably just going to get a complete set of stocks diffs from a brand new 3905 for $20 and see if thatll work.
although i do want to get some aluminum cases to protect that ring and pinion gear.
the only 3905 AL case i can find is this one, and the company isnt too reputative.
http://www3.towerhobbies.com/cgi-bin...&I=LXVBZ0&P=FR