Copyright by Goodheart-Willcox Co., Inc.
504 Auto Engine Repair
Figure 23-5. A—A driver is the best way to seat a crank-
shaft or camshaft sprocket. B—Fit the driver over the
sprocket and hit the driver with a hammer until the sprocket
is fully seated.
A
B
Figure 23-6. With the camshaft and crankshaft in the correct
positions, fit the chain and sprockets into place. The timing
marks on the sprockets should align.
Figure 23-7. Torque the camshaft sprocket fastener(s) to
specifications.
Camshaft sprocket Plated link
Mating mark
Timing chain
Mating mark
Plated link
Crankshaft
sprocket
Timing mark aligned
with a point on
the engine or
#1 piston on TDC
Timing mark aligned
with a point
on the engine
Figure 23-8. This engine has special chain links that should be
aligned with timing marks on the sprockets. (Chrysler)
7. Torque the camshaft sprocket fastener(s) to specifica-
tions. See Figure 23-7. Many engine builders like to
place a drop of thread lock on the camshaft sprocket
bolt(s). This will help keep the bolt(s) from loosening
during engine operation.
8. Double-check the alignment by turning the crankshaft
by hand until the timing marks realign.
Usually, tightening the fastener(s) or hand pressure
will slide the sprockets over the camshaft and crankshaft.
If not, use a large socket or driver and a hammer to exert
equal pressure in the center. This will drive the sprockets
on squarely. Do not hammer on the outside of the sprock-
ets to force them in place. Blows on the outside of the
sprocket may result in misalignment.
Figure 23-8 shows the timing mechanism for one
design of overhead camshaft engine. Note that the chain
has special plated or color-coded links. These must be
aligned with marks on the chain sprockets. The number
one piston must be at TDC on the compression stroke with
these marks aligned.