PS Magazine - TB 43-PS-681

PS, The Preventative Maintenance Monthly

ISSUE 681

AUGUST 2009
PS Magazine - TB 43-PS-681 - Page 8 of 33
12
PS 681
AUG 09
13
PS 681
Safety Overhead
Problem
mods
also
show
up on up-armored HMMWVs
with turret gunner protection
kits (GPK) or objective gunner
protection kits (O-GPK). These
mods add weight to the upper roof
and turret area of the HMMWV,
raising the center of gravity
(CG). That adversely affects
vehicle stability and drivability,
and leads to component fatigue
and overloading of the roof
support system.
Have You Seen These Mods?
Adding plates to up-armored HMMWV roof and armor plates and adding
additional ballistic glass to the O-GPK are problem mods. They can add about 600
pounds to the already heavy up-armored HMMWV! Extra weight on or near the top
of the vehicle increases the likelihood of vehicle rollover.
•
Installing bucket-style seats in your basic model HMMWV without using
conversion kit, NSN 2590-01-393-3796, and adapter kit, NSN 2540-01-429-9903—
for ambulances and shelter carriers only—is a problem mod. These kits provide
additional parts required to meet the approved conFguration.
Of course, this doesn’t complete the list of problem mods, but you get the picture.
All unauthorized mods should be removed from HMMWVs. All HMMWV Feld
mods MUST be authorized by PM-Light Tactical Vehicles before they can be
applied.
•
reduces the suspension travel beyond the limitations of HMMWVs equipped with
fragmentation kit 5 (FK5) and O-GPK. This degrades acceleration and fuel mileage, and
increases vehicle fatigue, ground clearance and braking distance.
•
negatively impacts weapon station readiness. The turret bearing reaches its load
carrying capacity with the application of O-GPK. Extra weight shortens turret ring
and battery life and slows down the rotation speed of the battery-powered motorized
traversing unit (BPMTU).
•
exceeds the capacity of the roof support system, leading to catastrophic roof cave-ins!
Heavy Weight Means Heavy Price
•
Removing the shelter from the M1037 or M1113 HMMWV and using the truck as
a cargo or troop carrier is a problem mod. The heavy-duty springs won’t compress
properly without the weight of a shelter carrier or a 1500-lb equivalent. The resulting
bounce can affect the driver’s ability to maintain control of the vehicle.
added
weight from
unauthorized
mods…
so remove all problem
mods to the roof of
up-armored hmmwvs and
gpk and o-gpk. then
plug any holes with
grade 8 fasteners.
I need my
shelter for
safe driving,
so
don’t
remove it!
ouch!
someone
added too
much weight
up there!
you gotta
be kidding
me!
I know!
I know!
Making your up-armored
HMMWV heavier without the
truck headshed’s approval
may cost you a heavy price.
681.12-13.indd
1-2
7/7/09
3:01:32 PM
Back to Top
Back to Top