the spacer allows the "block" or "stopper" part of the inner tie rod to be slighty further away from the rack. This allows a few more degrees bfore they finally contact.
From Mike aka DJElektrique:
"Here.... I made a diagram.
The green color is the spacer.
Notice how the rack will stop moving because
the opposite side (the red colored tie rod joint on the right) hits the rack, keeping it from turning anymore.
Well, add in the green spacers and you just made the rack longer and it will turn that much more before the red tie rod joint hits the rack. Easy as using brake cleaner to clean your hands. "
Here is the full thread on FA:
http://forums.freshalloy.com/ubbthre...e#Post67347302