I have to agree with Druss, rebuild everything! I got myself a Slash as a roller this past summer. Everytime I looked at it something else needed to be replaced. I have since replaced all wheel bearings (not Traxxas), front bulkhead, and rear gear case due to excessive wear. Wear to the point the a-arm pivots were so loose the arms would move a few degrees. Now I have RPM arms f/r, hub carriers f/r, caster blocks, and f/r shock towers. Two things I would do again in a minute are replacing the front body mount with a Stampeed mount. It holds the body just a little higher so there is no rubbing with the front tires. Also with the additional power from my 2S lipo I changed to 32 pitch gears. If you ever decide to go brushless it wouldn't be a bad idea anyway. This is real simple, for stock gearing use a Traxxas Jato spur gear 58 tooth, and a Robinson Racing 12 tooth pinion. Traxxas also makes 32 pitch gears for the E-maxx if you need to change the ratio. You'll have to loose the gear cover, but with 32 pitch, who cares.

On a side note many of the upgrades were recomendations from my fellow club memebers. Including this last one. To get the best power out of your batteries, loose the Traxxas plug and go Deans.