Do I need to buy 1 of these rack spacers or 2? You only need to buy 1 as buying 2 offers no benefit to the improvement of the steering lock. The way that these work is that they take advantage of extra travel available within the steering rack (which does have a limit). Hence the 1/2" (13mm) bolt on on the LH side of the rack and the 1/4" (6mm) washer on the RH side of the rack. Adding an extra rack spacer won't give more lock. In the event that your tie rod ends are too short then in that case using another bolt on rack spacer (on the RH side) would be okay. How does this steering rack spacer work? The steering rack spacer screws between the steering rack and your LH side tie rod. It allows the steering rack to travel an extra 1/2" (13mm) while the washer which is to be installed on the RH side allows for an additional 1/4" (6mm) of travel. Giving a grand total of 3/4" (19mm) of additional steering rack travel = 12-15 degrees more lock. I've installed the rack spacer and I've got a heap of toe in, what happened? After you have centred your rack (this is CRUCIAL) you may need need to trim your tie rod ends down to counteract the length that you've just put into the length of the rack. Whether you need to trim the tie rods down depends on your setup (Ie. if you've got longer LCA's or aftermarket knuckles you may not need to). Do NOT trim too much off or else you'll need to get a new tie rod and only trim down once you've centered the rack. Note that the LH side has a larger spacer so it will need the most attention. What's the difference between this screw on steering rack spacer and the lock washers that you sell? The steering rack spacer gives in total an additional 3/4'' (19mm) of travel where as the lock washers only offer 1/2'' (12mm) of travel (1/4'' (6mm) each)