I have no real proof on this, but I think the one of the reasons the steering rack breaks on the TC4 is that the servo saver spring digs into the plastic and weakens the component. Eventually everyone will break a steering rack on a TC4. When you buy your replacement rack, just use the shim/washer from the original rack on 1 side of the spring and the shim/washer from the new rack on the other side of the spring before you install it. Once I started doing this, I have had less issues with breakage.
Another thing that will always help is a wider front bumper. The stock bumper that comes with the car could be a bit wider. Parma used to sell a wider/harder bumper for the TC4, but it doesn't seem to be readily available. Parma still makes a generic bumper that can be cut to fit any car. Here is a link (
http://www3.towerhobbies.com/cgi-bin...?&I=LXPUR6&P=7).
Finally, if anyone is having issues with the screw coming loose on their servo saver, it is time to replace the locking nut (because the nylon in the nut has worn out). You could use Locktite (or similar) to secure the screw. But since it can be a pain to work on the rack, you might as well replace the nut while you are working on the steering rack.
I have found the easiest way to gain access to the steering racks on both the TC3 & TC4 is to remove the entire front diff case with the chassis braces still attached. Remove the 4 screws holding the diff case to the chassis, the 2 screws holding the front chassis braces to the chassis, the 1 screw holding the diff case to the upper bumper mount, pop off the ball cups holding the shocks on the a-arm, and finally pop off the inner ball cups from the front camber links. While this seems like a lot of effort, it really only takes a few minutes and you can remove this whole assembly and will have easy access to the steering and a-arms
Hope this info helps.