Is there normal for the drive cup to wobble abit?

[RC-Monster Mike]

If the diff outdrives are wobbling, it sounds more like the endcaps are worn. 1-2mm of play is pretty excessive movement. I grease my outdrives and haven't worn out any caps, but I do have steel endcaps available as an option parts - they are about 2x as heavy as the aluminum caps, but are hardened steel and should last pretty much forever. :)