Removal, Inspection, and Installation of Valve Springs

inch, they should have a load of 122- to 131-pounds.

CAUTION

Spring free length is 23 / 32 inches. Replace any springs

The rocker arms are not designed to

that are found to be weak or cracked.

contact the valve stems at the center,

(d) Install valve spring by a direct

but 1/16 inch off center. Do not

reversal of (b) above. Make certain that the release type

bend rocker arms to make them line

rotors (30, fig. 3-30) are installed on exhaust valve

up center-to-center with valve stems.

stems only.

(1) Make certain plugs are tight in ends of

(e) Install cylinder head (para 3-20).

shaft.

(2) Cylinder head not removed from engine.

(2) Install exhaust rocker arms (7, fig. 3-37),

(a) Remove rocker arm cover and

shaft support, and intake rocker arm (6) in order shown.

rocker arm assembly (c) above.

Assemble last half in same manner, then install second

(b)

Crank engine to make certain that piston

washer and cotter pin.

in cylinder from which valve springs are to be removed,

(3) Install oil tube elbow (12) and line

is at top dead center. Using two heavy screwdrivers, or

assembly (13) in collar at center of shaft. Make certain

suitable pry bars, and using the manifold as a fulcrum,

elbow enters hole in shaft.

pry down on valve spring retainer (28) until valve spring

(4) Install rocker arm assembly on cylinder

retainer locks (29) can be removed. Remove valve

head, making certain that shaft supports are positioned

spring retainer locks and carefully release tension on

with longer section down.

valve spring. Remove valve spring retainer and valve

(5) With valve lash adjusting screws (11)

spring.

correctly seated in push rods, tighten shaft support stud

nuts and capscrews. Torque to 18 to 22 ft-lbs.

(d) above.

(6) Install oil line assembly (5) between rocker

(d) Install rocker arm assembly and

arm shaft and cylinder head.

rocker arm cover (d above).

(7) Adjust valves for correct clearance (TM

h. Removal and Inspection of Valves, Guides, and

10-3930-618-201.

Seat Inserts.

(8) Install rocker arm cover making certain

(1) Remove rocker arm assembly. Refer to (

gasket is in good condition and properly positioned, then

c above).

install vent hose.

(2) Remove cylinder head from cylinder block.

e. Removal and Inspection of Lifters and Push

Refer to paragraph 3-20.

Rods.

(3) Remove valve springs. (Refer to ( g

(1) Remove rocker arm assembly (d above).

above).

(2) Withdraw push rods (23). Inspect ball and

(4) Remove valves from cylinder head. Place

cup ends for signs of wear; polish out any nicks or score

valves in a rack as they are removed from cylinder head

marks. If push rods are bent, twisted, or damaged they

so they can be identified and reinstalled in their original

must be replaced.

positions.

(3) If inspection indicates valve lifters (22)

(5) Clean carbon from valves and valve

should be removed, refer to paragraph 3-24.

inserts (21 and 22). Clean carbon from valve guides (14)

f. Installation of Lifters and Push Rods.

using a valve guide cleaning tool.

(1) Install lifters, reversing procedures in e

(6) Replace valves if they are cracked, bent,

above.

or worn beyond allowable limits. Specified diameter of

(2) Install push rods with cup end to top of

valve stems is 0.3405 inch to 0.3415 inch. Specified

cylinder head.

clearance of valve stems in valve guide is 0.0015 inch to

(3) Recheck to make sure that push rods are

0.0035 inch. If clearances exceed specified limits, valve,

firmly seated in lifters.

guide, or both should be replaced.

(4) Install rocker arm assembly and rocker

(7) Valve guides (14) are removed by

arm cover ( d above).

pressing them out through bottom of cylinder head, using

g. Removal, Inspection, and Installation of Valve

a valve guide removing tool.

Springs.

(8) New valve guides are installed by inserting

(1) With cylinder head removed from block.

upper (chamfered ) end of guide on guide installing tool

(a) Remove cylinder head (para 3-20).

and pressing into cylinder head until top of guide is 7 / 32

(b) Place cylinder head on end, depress

inch above top surface of cylinder head. Both intake and

valve springs (27, fig. 3-30) with a spring depressing tool

exhaust valve guides are positioned to the same depth in

and remove spring retainer locks (29). Release valve

head.

spring depressing tool and remove valve spring retainer

(9) After valve guides have been installed,

and valve spring.

insert valve stems into guides to check for proper

clearances between valve stems and valve guides.

Both intake and exhaust valve springs should have a

Specified clearance if 0.0015 inch to 0.0035 inch.

load of 42- to 47-pounds when compressed to length of 1

27 / 32 inch. When compressed to a length of 1 13/32

3-47