PS Magazine - TB 43-PS-582
PS, The Preventative Maintenance Monthly
ISSUE 582
MAY 2001
PS 582
MAY 01
7
PS 582
MAY 01
HMMWV.
..
➪
When
a
transfer
range
change is necessary with the
engine running, stop the truck
and shift the transmission to neu-
tral. Never shift on the fly. That'll
tear up driveline parts.
Shift the transfer shifter
forcefully through neutral to the
desired range. Some gear clash
may occur and is normal, but you
should be able to make the shift
easily. However, the longer you
leave the shifter in neutral, the
more gear clash will occur. That's
because even in neutral, engine
rotation spins the transmission
output shaft.
➪
If you can't shift easily, turn
the engine off and then shift the
transfer. Restart the engine and
continue the mission.
➪
When your mission is com-
plete, let your mechanic know
that you had to stop the engine to
shift the transfer.
G
rind your own teeth long enough, drivers, and your friendly dentist will have a
field day with you in the chair.
So, you'll understand that grinding is not good when you try to shift transfer gears
with the engine running on your HMMWV. It means that someday a mechanic may
have to repair gear damage.
When transfer shifting problems are
reported, check the engine idle rpm
before troubleshooting. The correct
idle speed for 6.2-liter engines is 650
rpm. For 6.5-liter engines, it's 750 rpm.
The amount of gear clash is related
to engine speed and to the length of
time the transfer is left in neutral with
the engine running.
Engine idle adjustment procedures
are on Page 3-83 of TM 9-2320-280-
20-2. Once the idle is adjusted, shift
the transfer to see if the adjustment
made any difference. If not, troubleshoot
the transfer.
After troubleshooting, if you find no
problems with the transfer, return the
truck to service.
For Mechanics
For Drivers
With engine running, shift through
NEUTRAL to desired range
Can’t shift with engine running?
Turn engine off, then shift
6
582. 06-07 (C)
4/4/01
9:45 PM
Page 1
Back to TopBack to Top
