TM 5-3895-382-24
No-Spin Differential Operation Test
1.
With the engine not running, raise the axle until the
wheels are not contacting the ground surface. Place a
blocking stand under the axle to block the wheels off the
surface.
2.
With the help of an assistant on the opposite side, start
the test by rotating both wheels in a forward direction as
far as possible. Both wheels should stop after rotating a
short distance.
3.
While the assistant holds the right wheel locked forward
against the stop, rotate the left wheel in a backward
direction. Listen for an indexing or clicking sound. (The
right wheel must be held firmly against the stop or the
left wheel will not disengage freely.) Grasp the left wheel
to stop its rotation. Then, move it slightly forward
(toward the stop). The NO-SPIN differential should lock
up.
4.
Rotate both wheels in a backward direction as far as
possible. Both wheels should stop after rotating a short
distance.
5.
While the assistant holds the right wheel locked against
the stop in the backward direction, rotate the left wheel
in a forward direction. Listen for an indexing or clicking
sound. (The right wheel must be held firmly against the
stop or the left wheel will not disengage freely.) Grasp
the left wheel to stop its rotation. Then, move it slightly
backward (toward the stop). The NO-SPIN differential
should lock up.
6.
Repeat Steps 2, 3, 4, and 5, with the left wheel blocked
against the stop and rotating the right wheel both in
forward and reverse.
7.
The steps are completed successfully if the rotated
wheels disengage easily by hand, they rotate freely and
evenly, and a faint indexing or clicking sound is heard.
The NO-SPIN differential is installed correctly and is
functioning correctly.
8.
If either wheel does not rotate freely in either direction, a
check of the NO-SPIN differential should be made.
9.
Check to see that both wheels of the NO-SPIN
differential are driving. Make this test under load, so
that engine torque is applied through the NO-SPIN
differential with the wheels on the ground. One way to
achieve this load is to drive up to a solid obstruction (on
loose dirt or gravel, if possible) and attempt to spin both
wheels together. Perform this test in forward and
reverse.
NOTICE
Do not operate the machine if both wheels of the NO-SPIN
differential are not driving.
10.
On a flat surface, with good traction, drive the machine
in a tight circle in forward and reverse to be sure that the
outside wheel is free to overrun (the outside tire does
not scuff). A clicking or indexing sound may be heard.
The sound of gear re-engagement may also be heard
upon completion of the turn. This is normal.
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