ok
1. make sure your exhaust wire is not binding against your steering

2. your diff oils may need to be changed, or losi may not have put the right oils in from factory, it has been done...7-10-2

3. make sure your wheel base is set right... should be 1 shim in front and behind the rear hub.

4. also make sure your bearings are good in the rear hub

5. how much droop you run?

check this, and get back to us...i garentee its one of these