Subaru Legacy 2004 Service Manual page 1169

Camshaft
MECHANICAL
6) Measure the side clearance of camshaft with dial
gauge. If the clearance exceeds the limit or has
partial wear, replace the caps and cylinder head as
a set. If necessary, replace the camshaft.
Standard:
0.068 — 0.116 mm (0.0027 — 0.0047 in)
ME-00121
ME(H4DOTC)-58