So I recently got a Rustler 4x4 ultimate. I love the car, looks awesome, super fun to drive. But, damn near every time I run a 3s battery, I break something driveline related. So far I've replaced the wheel hexes with aluminum ones. And got rid of the slipper clutch for a metal gear differential, the same one the hoss uses. Car kept chewing up spur gears, and the clutch always seemed loose, it would almost never wheelie and just had a lot of slip. I'm pretty happy with those upgrades. Also replaced a few driveshafts, but replaced with stock ones. I like the car but have been frustrated with it, and I feel like I mostly take it easy on it compared to my Maxx. I bash the Maxx, and have yet to have a single issue with it.

I'm thinking of upgrading to the Traxxas metal driveshafts,they are expensive but should hopefully last quite awhile. Also thinking of upgrading the differential to the better internal gears. Not sure what else I can/should upgrade.