RE: OFFICIAL TRAXXAS SLAYER OWNERS THREAD
The axle carriers are pretty common. I would ebay a set of Revo carriers, they have the metal ring on them to keep from breaking. You can get all 4 from a parted out truck with all the bearings and everything for 20 bucks shipped. While your on there you should get a swaybar kit, and stiffer springs. If you are on a budget just get the next rate up from the rear and move the rears to the front. If no budget you can read this thread and see all the upgrades everyone else did.