GMC T Series 1994 Repair Manual page 539

A. SEAL, EXHAUST VALVE STEM
207. VALVE, INTAKE
208. VALVE, EXHAUST
210. SHIM
406. VALVE KEEPER
407. CAP
408. SHIELD
409. SEAL, VALVE
410. VALVE SPRING WITH DAMPER
411. ROTATOR
B. Install the retainers with a drift of at least
13-mm (1/2-inch) diameter.
HYDRAULIC LIFTERS
Hydraulic lifter rollers for fatigue or pitting, replace
lifter as as an assembly.
Important
Some engines will have both standard and a
0.010-inch oversize hydraulic lifters. The oversize
lifter will have a " 10" etched on the side. The block
will be stamped "O.S." on the cast pad adjacent to
the lifter bore and on the top rail of the cylinder
case above the lifter bore.
CYLINDER HEAD
The 6.5L light duty naturally aspirated engine uses a
39-mm (1.53-inch) non-stellite exhaust valve. Both tur­
bocharged and heavy duty naturally aspirated engines
use a 39-mm (1.53-inch) stellite face exhaust valve. All
engines use the same size intake valve that is 46 mm
(1.81 inch). Intake and exhaust valves with oversize
stems are available in 0.09 mm (0.03 inch) and 0.39
mm (0.153 inch) oversize.
Disassemble (Figures 52, 53, and 54)
❖
Tool Required:
J 8062 Valve Spring Compressor
Figure 52—Valves and Components
1. Valve keepers (170).
2. Caps (407), rotators (411), shields (408), valve
3. Valve seals (409).
4. Valves (207 and 208). Place them in a rack so they
411
A. Compress the valve springs with J 8062 (figure
53).
B. Remove the valve keepers.
C. Remove J 8062.
springs with dampers (410) and shims.
can be returned to their original position at assem­
bly.
406
406
V3876