I thought my TC was broken when I first got it. Of course, it had been decades since I'd driven a HMMWV and I didn't remember this (see section in BOLD). Works GREAT when engine's stopped, transmission in neutral. No grinding then.
NB
TM-9-2320-280-10
2-108
Change 1
2-11. PLACING VEHICLE IN MOTION
WARNING
•
This vehicle has been designed to operate safely and efficiently
within the limits specified in this TM. Operation beyond these
limits are prohibited IAW AR 750-1 without written approval from
the Commander, U.S. Army Tank-automotive and Armaments
Command, ATTN: AMSTA-CM-S, Warren, MI 48397-5000.
•
Communications shelters AN/GRC-122 and AN/GRC-142 RATT
may overload truck by up to 500 lbs (227 kg). Use caution when
driving to avoid damage to equipment or injury to personnel.
NOTE
The following procedures apply to a vehicle being driven in good
weather on high traction surfaces where little or no wheel slippage
is evident. For operating the vehicle under unusual conditions; i.e.,
unusual terrain, cold weather, ice, snow, dusty or sandy areas, mud
or rain, refer to section IV.
a.
Be sure all auxiliary equipment and tools are stored for travel.
CAUTION
• Vehicle must be stopped, engine off, and transmission shift lever
placed in “N” (Neutral), before transfer case can be shifted.
Failure to do this will result in damage to drivetrain.
•
Do not place transfer case shift lever in “H/L” (high lock range) or
“L” (low range) on high traction surfaces where little or no wheel
slippage is evident, particularly when encountering sharp,
continuous turns. Failure to operate the vehicle with transfer case
in “H” (high range) on high traction surfaces, particularly when
encountering sharp, continuous turns, can damage drivetrain.
b.
With transmission shift lever (2) in “N” (neutral), select “H” (high range)
transfer case driving gear range using transfer case shift lever (3). This range is
for normal driving in good weather, or on high traction surfaces.
