Pontiac FIREBIRD 1972 Service Manual page 543

SIX CYLINDER ENGINE 6-3 1
Remove valve cover and gasket, loosen valve rocker
arm nuts and pivot rocker arms clear of push rods.
Remove distributor, fuel pump and spark plugs.
Remove coil, push rod covers and gasket. Remove
push rods and valve lifters.
-
Remove harmonic balancer using tool 5-6978.
Loosen oil pan bolts and allow oil pan to drop away
from timing gear cover. Remove timing gear cover.
Remove the two camshaft thrust plate screws by
working through holes in the camshaft gear (Fig.
6-46).
Remove the camshaft and gear assembly by pulling
it out through the front of the block. (Support shaft
carefully when removing so as not to damage cam-
shaft bearings).
DISASSEMBLE
1. If the gear must be removed from the shaft, use press
plate J-947 and adaptor J-22227 on press.
2. Place tools on table of a press. Place the camshaft
through the opening in the tools. Press shaft out of
gear using socket or other suitable tool (Fig. 6-47).
CAUTION: Thrust plate must be so positioned
that woodruff key in shaft does not damage it
when the shaft is pressed out of gear.
ASSEMBLE
To assemble camshaft gear, thrust plate and gear spacer
ring to camshaft, proceed as follows:
Fig. 6-46 Removing Camshaft Thrust Plate Screws
Fig. 6-47 Removing Camshaft Timing Gear
1. Firmly support shaft at back of front journal in an
arbor press using press plate adaptors.
2. Place gear spacer ring and thrust plate over end of
shaft, and install woodruff key in shaft keyway.
3. Install camshaft gear and press it onto the shaft using
tool shown in Fig. 6-48 until it bottoms against the
gear spacer ring. The end clearance of the thrust plate
should be .001" to .005" (Fig. 6-48). If less than
.00lU, the spacer ring should be replaced. If more
than .005", the thrust plate should be replaced.
REPLACE
Install the camshaft assembly in the engine block,
being careful not to damage bearings or cams.
Turn crankshaft and camshaft so that the valve tim-
ing marks on the gear teeth will line up. Drive cam-
shaft and geqr on using J-5154. Install camshaft
thrust plate to block screws and tighten to 5-8 lb. ft.
Check camshaft and crankshaft gear runout with a
dial indicator (Fig. 6-49). The camshaft gear runout
should not exceed .004" and the crankshaft gear run-
out should not exceed .003".
If gear runout is excessive, the gear will have to be
removed and any burrs cleaned from the shaft or the
gear replaced.