Wear
3. A slightly worn lobe still within ac-
Shaft Journal Fillets
ceptable limits, may be stoned and
smoothed over with a fine crocus cloth.
2. Leave a 0.010" to 0.030" radius be-
tween the bearing surface of the thrust
Check the runout at the center bearing
collar shoulder and the bearing surface
with the camshaft mounted on the end
Runout s h o u l d n o t
of
bearing surfaces.
the
balance
shaft
(see
exceed 0.002".
Use a fillet gauge to measure the speci-
Examine both faces of each camshaft rear
Also,
end bearing and thrust washer.
examine t h e s u r f a c e s o f e a c h c a m s h a f t
Examine the faces of the shaft end bear-
and camshaft gear which contact the
ings and any other surface which comes
Replace
excessively
thrust
washers.
into contact with the thrust washers.
w o r n o r s c o r e d p a r t s . Camshaft or cam-
Parts that are badly marred must be
shaft gear thrust surfaces that are not
placed; parts with slight scratches may
scratched too severely may be smoothed
b e cleaned up with an oil stone.
d o w n with an oil stone.
NOTE
NOTE
is
to
be
If
a
new
camshaft
is to
be
new
camshaft
If
a
installed, steam clean it to remove
installed, steam clean it to remove
the rust preventative and blow out
the rust preventative and blow out
the oil passages with compressed
the oil passages with compressed
air.
air.
Inspect the bushings in the shaft end
New standard size thrust washers are
Replace the bushings or end
0.120" t o 0 . 1 2 2 " t h i c k .
The clearance
bearing assemblies if they are worn ex-
between the thrust washer and the
cessively or the bushings have turned
thrust shoulder of the camshaft is 0.004"
within the bearing.
New bushings must
t o 0.012" with new parts or a maximum of
be finished bored to 20 rms finish after
0.018" with used parts. Excessive clear-
installation a n d t e s t e d f o r t h e c o r r e c t
ance m a y b e r e d u c e d b y u s i n g t h r u s t
press fit. The correct press fit is indi-
washers which are 0.005" or 0.010" over-
cated if the bushing does not move when
size.
a 2000 pound (8.9 kN) end load is ap-
This test is of special importance
plied.
When the thrust surfaces of a camshaft
with engines that operate at high (2300
or balance shaft are ground undersize,
RPM) speeds. The inside diameter of the
special care must be taken as follows:
bushings must be square with the rear
face of the bearing within 0.0015" total
1. Leave a 0.031" to 0.094" radius be-
indicator reading and concentric with the
tween the bearing surface of the thrust
outside diameter of the bearing retainer
collar shoulder and the bearing surface
within 0.002" total indicator reading.
The bushings must project from 0.045" to