Inlet Valve Adjustment; Exhaust Valve Adjustment - Mack E7 Service Manual

5-101.bk Page 5 Friday, March 17, 2006 11:05 AM
CHECKING YOKE ADJUSTMENT
Refer to Figure 7-4.
1. Insert a 0.010-inch (0.254 mm) thickness
gauge between the yoke and valve stem, at
both the inboard and outboard locations.
2. Exert moderate force on the yoke by
pressing on the rocker arm slipper end. An
equal drag should be felt on both thickness
gauges. If drag is unequal, readjust the yoke
adjusting screw, as required.
Figure 7-4 — Checking Yoke Adjustment
1. Thickness gauge

Inlet Valve Adjustment

Refer to Figure 7-5.
Inlet valve lash clearance is 0.016 inch
(0.406 mm).
1. Place a 0.016-inch (0.406 mm) thickness
gauge between the rocker arm and yoke on
the No. 1 cylinder.
2. Turn the adjusting screw until a light drag is
felt on the thickness gauge.
3. After setting adjustment screw, tighten
locknut. Torque locknut to 40 lb-ft (54 N•m)
using torque wrench J 24407 or equivalent.
Do not allow the adjustment screw to turn.
4. After tightening locknut, recheck valve lash
clearance. Readjust as necessary.
200 SETUP AND ADJUSTMENTS
2. Yoke
Figure 7-5 — Inlet Valve Adjustment
1. Thickness gauge 2. Adjusting screw and

Exhaust Valve Adjustment

Refer to Figure 7-6.
Exhaust valve clearance is 0.024 inch
(0.610 mm) for engines produced through engine
serial No. 6F in April 1996 and 0.028 inch
(0.711 mm) for engines produced after engine
serial No. 6F in April 1996.
1. Place the proper thickness gauge between
the rocker arm and yoke on the No. 1
cylinder.
2. Turn the adjusting screw until a light drag is
felt on the thickness gauge.
If equipped with a Dynatard engine
brake, use Dynatard valve-lash adjusting
wrench J 37092 to rotate adjusting
screw. Press downward with hand on the
hydraulic lash adjuster while gauging
valve lash. Adjust the lash until a light
drag is felt on the thickness gauge.
3. After adjustment is complete, tighten
locknut. Torque locknut to 40 lb-ft (54 N•m)
using torque wrench J 24407 or equivalent.
Do not allow the adjustment screw to turn.
4. Recheck valve lash clearance after
tightening locknut. Readjust as necessary.
locknut
Page 7-5