Fork - Inspect - Doosan D50S-5 Operation & Maintenance Manual

Fork – Inspect
Forks should be inspected, at a minimum, every 12
months. If the truck is being used in a multi-shift or
heavy duty operation, they should be checked every
six months.
1. Inspect the forks carefully for cracks. Special
attention should be given to the heel section (A),
all weld areas and mounting brackets (B).
Inspect the top and bottom hooks on forks used
on hook type carriages and tubes on shaft
mounted forks.
Forks with cracks should be removed from
service.
"Wet Test" magnetic particle inspection is
generally preferred due to its sensitivity and the
ease of interpreting the results. Portable
equipment is usually recommended so it can be
moved to the lift truck.
Inspectors should be trained and qualified in
accordance with The American Society for Non
Destructive Testing, Level II Qualifications.
2. Check the angle between the upper face of the
blade and the front face of the shank. The fork
should be withdrawn from service if angle (C)
exceeds 93 degrees or deviates by more than 3
degrees from an original angle other than 90
degrees, as may be found in some special
application forks.
3. Check the straightness of the upper face of
blade (D) and the front face of shank (E) with a
straight edge.
The fork should be withdrawn from service if the
deviation from straightness exceeds 0.5 percent
of the length of the blade and/or the height of the
shank respectively 5 mm/1000 mm (0.18"/36").
4. Check the difference in height of one fork tip to
the other when mounted on the fork carrier. A
difference in fork tip height can result in uneven
support of the load and cause problems with
entering loads.
The maximum recommended difference in fork
tip elevation (F) is 6.5 mm (0.25") for pallet forks
and 3 mm (0.125") for fully tapered forks. The
maximum allowable difference in fork tip
elevation between the two or more forks is 3
percent of blade length (L).
Replace one or both forks when the difference in
fork tip height exceeds the maximum allowable
difference. Contact your local DOOSAN Lift
Truck Dealer for further information.
195
Maintenance Section