Check the side gear spline fit on an axle shaft. Be sure
Checking NoSPIN Performance in the Vehicle
the splines do not bind.
If the complaint is Locking, Tire scuffing or Tire wear,
Assemble the NoSPIN, being careful to position the
drive the vehicle in a tight circle on concrete. The outside
spring retainers so that the spring seats inside the cupped
tire should rotate faster than the inside tire due to its greater
are of travel. There should be no evidence of tire slipping or
A bolt and washers can be used to hold the NoSPIN
assembled, provided the washers are small enough to
NOTE: Extremely short wheelbase vehicles having very
pass through the differential case ends after the case
short turning circles may not have enough traction
bolts are tightened. If this retainer bolt is not available, it
to drive the vehicle by the inside wheel. It will then
is quite easy to assemble by hand pressure, holding in
slip and rotate at the same speed as the outside
position until a case bolt is started.
wheel when driving. This can occur on small fork
Before installing NoSPIN and case assembly in the
lift trucks, or very short wheelbase trucks.
carrier, again place an axle shaft into each side gear and
If a Standard-type NoSPIN is being checked, a uniform
rotate. It should be possible to feel the backlash between
click or indexing sound will be heard. This indexing sound is
the clutch teeth (about 5"). If this backlash cannot be felt,
more difficult to detect on heavy vehicles and will not be
and the side gear is locked solid in the NoSPIN, remove
heard at all if a Silent-type NoSPIN is being checked.
the NoSPIN and check for thrust washers or wrong side
Try this while turning both left and right. If there is no
differential action, tire scuffing will result and the NoSPIN
Assemble the NoSPIN, case and ring gear assembly
must be removed for inspection.
into the carrier and re-assemble the axle in the usual
Another check to determine if the NoSPIN is locked up
is to raise both wheels off the floor and rotate one wheels
forward while an assistant holds the opposite wheel firmly
Lightly lubricate all parts of the NoSPIN as it is being
rearward. (Leave truck in gear with engine off). Repeat this
test holding the opposite wheel rearward. Then repeat test
No special lubricant is necessary. The NoSPIN will
operate well in any lubricant as recommended by the
vehicle or axle manufacturer.
direction on both sides. The rotating wheel should cam
at near full throttle. Not completely conclusive, but of some
out easily by hand and a series of uniform clicks will be
value, is a test made by spinning the wheels in low gear
heard if operating properly. There will be only slight clicks
while the truck is in -bumper contact with a solid object.
audible from the Silent-type NoSPIN. If the wheels
(Another truck can be used with the brakes locked). A
cannot be rotated freely as described above, remove and
gravel surface would be less likely to damage the vehicle
inspect the NoSPIN.
during this test. If a loud snap results or complete loss of
If the complaint is jerking, determine if this occurs as
power to one wheel occurs, the NoSPIN should be removed
the throttle is advanced at moderate speeds on the
highway or when pulling in low gear under high engine
torques. Unequal tire rolling radii due to wear, unequal air
A certain amount of backlash exists in the NoSPIN.
pressures or load on one side can cause jerking at normal
This space is necessary to. allow the clutch teeth to dis-
highway speeds with a throttle change. This will also
engage when turning corners. Actually it amounts to about
cause a continuous clicking in the NoSPIN which can be
A5' but is greater at the propeller shaft because it is
heard in light trucks using the Standard-type NoSPIN.
multiplied by the axle ratio.
Check the tire pressures. If jerking
This backlash can amount to Y/ to 1V turn of the
or clicking continues, check the rolling radii from the
ground to the rim or ground to axle shaft flange. This
shaft as it includes additional clearances such as splines
distance must be reasonably equal on each tire.
and gear tooth clearances. It is not detrimental to NoSPIN
The rolling diameters of the rear tires can also be
performance or vehicle and does not indicate a defective
checked by placing chalk marks opposite each other on
the rear tires. Drive the truck a short distance in a straight
A throttle change may result in an occasional single
line. If the rolling diameter is off, the marks will be in a
snap. This is caused by the sudden release of drive from
different location. Correct be changing air pressure in
one clutch to another due to momentary partial engagement.
present tires until chalk marks remain in same relative
This occasional snap does not indicate a defective unit.
It is a normal characteristic of the NoSPIN, more noticeable
If the NoSPIN has worn clutch teeth, they may slip out
in light vehicles.
of engagement under heavy torque loads, resulting in a
For complete description of the NoSPIN, see the opera
loud snap and severe jerk of the vehicle. This may occur
in low gear