National Crane 600H, Service Manual

Page: 206 / 232

CRANE INSTALLATION 600H SERVICE
9-24
08-19-2022 Control # 092-13
9. Install the inner bolt (11) and washer assembly, making
sure it passes through the hole in the anchor retaining
bracket (12) located on the inside of the frame channel.
10. Install plate (13) to outside bottom of the frame.
11. Install the hardened washer (10).
12. Install the DTI crush washer (9) with the bumps facing
towards the hardened washer (8).
13. Install the standard SAE washer (10).
14. Install the nut (14).
15. Snug all bolt arrays in a star pattern.
16. Tighten evenly in a star pattern until the direct tension
indicator (DTI) crush washer (9) compresses and the
silicon indicator is visible between the washers.
NOTE: The DTI crush washer cannot be re-used and must
be replaced if the studs are removed.
NOTE: Tighten only until the DTI crush washer (9) is
compressed and the silicon indicator is visible
regardless of the tension value applied.
Tension should be verified by inserting 0.127mm
(.005 in) feeler gauge between the hardened
washer and the DTI crush washer in between each
bump. An example of the acceptable tension would
be the refusal of the feeler gauge at least half way
around the DTI washer with 4 or more out of 7
insertions of a feeler gauge entering into the gap
between washers but not touching the bolt.
Maintaining proper tension for bolts is extremely important
for structural strength, performance, and reliability of the
crane. Variations in tension can cause distortion, binding, or
complete separation of the turret from the frame.
Proper identification of bolt grade is important. When marked
as a high strength bolt (grade 8), the service technician must
be aware of bolt classifications and that he is installing a high
strength heat-treated tempered component and the bolt
must be installed according to specifications. Special
attention should be given to the existence of lubricant and
plating that will cause variation from dry tightening values.
When a high strength bolt is removed, or un-tightened, the
b o l t m u s t b e r e p l a c e d w i t h a n e w b o l t o f t h e s a m e
classification.
Before performing the following procedure refer to Torque
Wrenches , page 1-8 on the proper use of a torque wrench.
Torsion Box Mounting
1. Position the torsion box assembly onto the frame.
2. Assemble the nuts (4, Figure 9-8), washers (6), studs (2)
and plate, clamp (5) and attach torsion box to frame.
3. Install the stud assembly through anchor retaining
bracket (3), locating it inside the frame channel.
NOTE: Cut the anchor retaining bracket (3) for the inner
anchor and neatly machine as necessary to fit
inside the truck frame.
4. Install the inner bolts (2) making sure it passes through
the hole in the anchor retaining bracket (3) located on
the inside of the frame channel.
5. Install plate (5) to outside bottom of the frame.
6. Install the hardened washer (6) and nut (7).
7. Snug all bolts in a star pattern.
8. Torque nuts (4 and 7, Figure 9-8) to 1084.7 Nm (800 ft-
lbs).
Follow proper procedure referencing Torque Wrenches ,
page 1-8 on the proper use of a torque wrench.
Mounting the 684TM
The 684TM crane frame is mounted with the outriggers. See
600H-TM Outrigger Assembly , page 7-10 for outrigger
mounting instructions.
WARNING
Crushing Hazard!
It is mandatory that T-box attaching bolts be inspected
and re-tightened after the first 300 hours of crane
operation and every 500 hours thereafter. The bolts may
loosen and cause the crane to separate from the carrier
which will result in damage to the crane and possible
injury or death to personnel.
!
CAUTION
Repeated re-tightening may cause bolts to stretch. If bolts
keep working loose, they must be replaced with new bolts
and DTI of the proper grade and size.
REFERENCE ONLY