Chevrolet CHEVY VAN G10 SERIES Service Manual page 165

ENG INE 6-36
Fig. 2 0 V —Removing Crankshaft Sprocket
Timing Chain and/or Sprockets
Replacement
1. Remove torsional dam per and crankcase fro n t cover as
outlined.
2. C rank engine u ntil m arks on cam shaft and crankshaft
sprockets are in alignm ent (Fig. 19V).
3. Remove cam shaft sprocket to cam shaft bolts.
4. Rem ove cam shaft sprocket and tim ing chain together.
S procket is a light press fit on cam shaft. If sprocket does
n o t com e o ff easily, a light blow on the low er edge o f the
sprocket (w ith a plastic m allet) should dislodge the
sprocket.
5. If crankshaft sprocket is to be replaced, remove sprocket
using Tool J-5825 (Fig. 20V ). Install new sprocket using
a b o lt and n u t from J-23523 (Fig. 21V).
Fig. 21 V —Installing Crankshaft Sprocket
J-5825
Fig. 2 2 V —Installing Tim ing Chain
6
. Install tim ing chain on cam shaft sprocket. Hold the
sprocket vertical w ith th e chain hanging dow n and align
marks on cam shaft and crankshaft sprockets (Fig. 22V).
N O T E : Do not attem p t to drive sprocket on cam­
shaft as welsh plug at rear of engine can be
dislodged.
7. Draw cam shaft sprocket o n to cam shaft, using the three
m ounting bolts. T orque to specifications.
8
. L ubricate tim ing chain w ith engine oil.
9. Install crankcase fro n t cover and torsional dam per as
outlined.
Camshaft
Measuring Lobe Lift
N O T E : Procedure is similar to th at used for check­
ing valve tim ing. If im proper valve operation is
indicated, measure the lift of each push rod in
consecutive order and record the readings.
1. Remove the valve m echanism as outlined.
2. Position indicator w ith ball socket ad ap ter (Tool J-8520)
on push rod (Fig. 23V ).
N O T E : Make sure push rod is in the lifte r socket.
3. R otate th e crankshaft slowly in the direction o f rotation
C H E V Y V A N SH O P M A N U A L