stitchy i had weird steering problems on the weekend. I ended up changing out the servo/servo saver/servo mounts with another car and that fixed the problem. I suspect it was the servo but the servo mounts i swapped in were aluminium ones so there wouldve been less chance of movement.
Also another stupid thing ive done before is that i forgot two screws when servicing the gears. which fix in the center of the chassis (ie the screws from one side which fix the front and rear halves of the chassis)