DESCRIPTION AND OPERATION
Page 57
Pinless Valve Yokes — Inlet and Non-Brake
Exhaust Valve Locations
Approximately two years prior to ASET™ engine
introduction, MACK standardized the use of
pinless valve yokes at all inlet valve locations,
together with standard push rods. Effective May,
2003, pinless yokes are also used at exhaust
valve positions of non-brake engines with
spring-loaded push rods. As a result, valve yoke
guide pins at the inlet and non-brake exhaust
valve locations have been eliminated from the
cylinder heads.
For pinless yokes at the exhaust positions of
non-brake engines, the spring-loaded push rods
are mandatory.
The pinless yoke is self-leveling in operation and
does not have a yoke leveling adjustment screw.
Inlet and non-brake exhaust valve lash
adjustments are performed in the normal manner
with the rocker arm adjusting screw. For the
engine brake exhaust valves, it is still necessary
to adjust the valve yoke first, then the rocker arm
lash.
The bottom of the valve yoke that bridges the two
valves has a round hole and an elongated hole
that fit over the valve stems. The nose of the yoke
with the elongated hole has two notches in the
casting. When installing the pinless yokes, it is
important that the end of the yoke with the two
notches faces away from the valve rocker shaft. If
the yoke is installed incorrectly, the yoke will
contact the rocker arm.
63
Figure 63 — Proper Assembly of the Pinless Valve Yoke
5-111.bk Page 57 Monday, July 10, 2006 2:26 PM
Summary of Contents for ASET AC
Page 6: ...TABLE OF CONTENTS Page iii TABLE OF CONTENTS 5 111 bk Page iii Monday July 10 2006 2 26 PM...
Page 14: ...INTRODUCTION Page 1 INTRODUCTION 5 111 bk Page 1 Monday July 10 2006 2 26 PM...
Page 23: ...Page 10 NOTES 5 111 bk Page 10 Monday July 10 2006 2 26 PM...
Page 96: ...COMPONENT LOCATOR Page 83 COMPONENT LOCATOR 5 111 bk Page 83 Monday July 10 2006 2 26 PM...
Page 99: ...Page 86 NOTES 5 111 bk Page 86 Monday July 10 2006 2 26 PM...
Page 100: ...TROUBLESHOOTING Page 87 TROUBLESHOOTING 5 111 bk Page 87 Monday July 10 2006 2 26 PM...
Page 140: ...MAINTENANCE Page 127 MAINTENANCE 5 111 bk Page 127 Monday July 10 2006 2 26 PM...
Page 153: ...Page 140 NOTES 5 111 bk Page 140 Monday July 10 2006 2 26 PM...
Page 383: ...Page 370 NOTES 5 111 bk Page 370 Monday July 10 2006 2 26 PM...
Page 479: ...Page 466 NOTES 5 111 bk Page 466 Monday July 10 2006 2 26 PM...
Page 480: ...SPECIFICATIONS Page 467 SPECIFICATIONS 5 111 bk Page 467 Monday July 10 2006 2 26 PM...
Page 505: ...Page 492 NOTES 5 111 bk Page 492 Monday July 10 2006 2 26 PM...
Page 513: ...Page 500 NOTES 5 111 bk Page 500 Monday July 10 2006 2 26 PM...
Page 519: ...Page 506 NOTES 5 111 bk Page 506 Monday July 10 2006 2 26 PM...
Page 520: ...APPENDIX Page 507 APPENDIX 5 111 bk Page 507 Monday July 10 2006 2 26 PM...
Page 528: ...INDEX Page 515 INDEX Index fm Page 515 Monday July 10 2006 2 48 PM...
Page 535: ...Page 522 NOTES Index fm Page 522 Monday July 10 2006 2 48 PM...