Struggled myself a little with the Tamiya servo saver, to get the little slop away.
Learned that some put a drop of superglue in the saver to keep it slop free, and the impact from a hard crash would break the glue, allowing the servo saver to operate as intended.
Guess even if the steering in itself are moving without binding, there should not be excessive slop either in the steering links, which could cause the car not center properly.