Replacing Steering Rack Mounts

[hks_kansei]

The bush should be split on both sides, most likely the split on one side is just caked in sh*t can you cant see it.
(edit: you're talking about the rack mount bushes yeah? not the actual subframe)

as for the lash, can't help with the setting etc, but to remove the cap rather than finding a huge allen key (which will cost a shitload) just measure and get a nut that fits in the hole.
the hole is shallow so the other half of the nut will be sitting proud, and should be plenty for you to grab with a shifter/spanner and turn.

bonus is, a nut will generally only be a couple of dollars, or free.

from memory the size will be close (same?) as the hub nuts on the car.