RE: [ihc] HMMWV, Hummer and other two-piece wheels...

["Mac @ TRIAD" <mac@xxxxxxxxxxxx>]

## >> The wheels on these trucks are indeed tubeless.  They actually have an
## >> O-ring between the halves when they bolt together.
## >> The nuts holding the two halves are also different than your
## >> average nuts.
## >> (giggling subsides...)
## >> The nuts on the halves are 5-sided and require a special tool, and are
## >> technically -NOT- field serviceable,
## >> which is why the HMMW, and Hummer, etc. come with what is
## >> called Run-flat,
## >> which is a large Aluminum or Magnesium annulus that
## >> mounts inside the tire and provides a ride height suitable
## >> for driving at a
## >> considerably reduced speed but is rated for ~50 miles,
## >> a distance determined to be enough to rid a driver/team of
## >> danger.  The
## >> 5-point socket does not come with the truck and is usually
## >> only found in
## >> the motor pool shop.  The mounting studs for the wheel to the
## >> hub are still
## >> the requisite 8 lugs that most 3/4T trucks have.

funny, but intellectually, i knew the HMMWVs are tubeless.  they run
Goodyear 36" to 38" radials here and many of them (though by no means all)
have the CTIS air control system.  i don't think that system works with
tubed tires, does it?  i should have thought about that before i asked the
question.  untill this discussion came up, i did *not* know those wheels
were 2-piece, however.  i never really thought about what that ring of nuts
around the hub were for, but now it all falls into place.

i do not know if the military HMMWVs prior to 2001 carried five or six-sided
lug wheel locking nuts, but i've seen a few articles that indicate even the
military trucks had the 5-sided nuts untill a specific point in time.  i do
know that all the HMMWVs here on post have six-sided wheel locking nuts, and
according to all the sources i could find, that change occurred with all
military HMMWV variants somewhere in the 2000-2001 time period.  we only got
here in 2002, and they were already like that.  when Joel mentioned the
five-sided wheel locks, i had to run over to the Brigade HQ and look at the
Commander's HMMWV to check and make sure i wasn't seeing things, 'cause i
haven't seen any five-sided nuts, Joel's post, i didn't know that they used
to have 5-sided nuts.  yup, six sided nuts on all three HMMWVs parked at
Brigade.

comment about the 5-sided nut tool:  my beautiful Soldier is now a member of
System Maintenance instead of Launcher Platoon.  she says that when their
tools haven't been borrowed, stolen, or lost, they're supposed to have all
the tools for the trucks and equipment, including that wheel nut tool, in
the BMC (no i don't know what that stands for), which is the field tools and
parts semi-truck for Maintenance Platoon (it's a 5-ton tractor and
workshop-on-wheels semi-trailer).  while the regular motor pool bays have
several sets of those tools for each Battery, they're supposed to have a
full set in each Battery's BMC as well.

and here's a nice helpful note:  many of the HMMWVs here do *not* have that
run-flat insert in them.  i can't tell you how many of their trucks my
lovely Bride's unit has had drop out of their convoys on the way out to do
field exercises and back  because they get flats along the way and don't
have those inserts.  none of them carry spare tires or tire changing tools,
either.  as it happens, a lot of the five-tons *also* do not carry spares or
tire changing tools.  all the HEMTT trucks carry spares, though.  not that
the truck's crew have the tools on hand to change a HEMTT tire and wheel.
they have to wait for the wrecker to come back for them when they lose a
tire, just like the rest of the trucks.  which is odd...  isn't this the
reason they have dual driven steering axles and dual or triple rear drive
axles?  for increased mobility in case of rough terrain or loss of tires?
(HEMTT stands for Heavy Expanded Mobility Tactical Truck, the most recent
upgraded version is rated as an 11-ton offroad and 22-ton onroad truck; all
HEMTTs have two driven steering axles and either two or three driven load
bearing axles).

i don't know if it's the same policy at other posts, but *here*, if a
vehicle drops out of a convy, they leave it, and its crew, and send the
wrecker back for it *after* the rest of the convoy has reached their field
location.  is that the way they do things when on a combat deployment?  i
don't know.  while they were off at the Iraq war, in the several convoys
they had to run, her battalion didn't lose any vehicles.  i don't think i
care to speculate on what Captain America (her Battery Commander) or the
First Sergeant would have done if they had.  neither of them is well-known
for their concern for the wellbeing of their troops.

--Mac

---------------------------------------------------------------
Take care and be well, all thee and thine;

May the Hamr lend thee Strength and Courage,
May the Twin Ravens lend thee Wisdom and Guidance,
May the Wolves Guard and Protect thee, and
May the Light of Harmony ever shine brightly upon thee and thine,
Through all thy Life's Journeys, from this life unto the next!

Hail the Gods and Goddesses of our Folk!
Wassail!

Krystof "Mac" MacBryghde
TyrGothi

http://master.triad.ath.cx/