Service manual

G420F(FE) Service Manual Chapter 3. Engine Mechanical System 71
VALVE GUIDE REPLACEMENT
Because the valve guide is press-fitted, replace the
valve guide as the following procedures using a
valve guide installer or proper tool.
1. Remove the valve guide pressed toward cylinder
block using a push rod of valve guide installer.
2. Cut the valve guide insert bore of the cylinder
head to the valve guide oversize.
3. Press-fit the valve guide using a valve guide
installer or proper tool. When using a valve guide
installer, Use a valve guide installer to press-fit the
valve guide to the specified height.
4. When installing, start from top of valve guide
cylinder head.
Be sure that the intake valve guide is not same
size with the exhaust valve guide. (Intake valve
guide : 46.0mm, ex-haust valve guide : 54.5mm)
5. After installing the valve guide, insert a new valve
and check for perturbation.
6. When replacing the valve guide, check the valve
for con-tact and correct the valve seat if
necessary.
Valve guide oversize
Size Size mark Cylinder head bore size
0.05 OS 5 11.05 ~ 11.068mm
0.25 OS 25 11.25 ~ 11.268mm
0.50 OS 50 11.50 ~ 11.518mm