TRUCK SERVICE MANUAL
Section 8. WEAR LIMITS AND SPRING DATA
f. Hook-type Sealrings. Sides of the sealring
SCOPE OF SECTION 8
should be smooth (maximum wear 0.005 inch (0.13
mm)). The sides of the groove into which the sealrings
This section tabulates wear limits and
fit should be smooth (50 microinch (1.
equivalent), and square with the axis of rotation within
0.002 inch (0. 05 mm). A new sealring should be
installed if grooves are reworked, or if there is wear on
the sealring outside diameter.
WEAR LIMITS DATA
g. Oil Seals. Seals should be replaced if they show
a. Maximum Variations. Wear limits information in
signs of excessive hardening, sc o ring, cracking or other
this section shows the maximum wear at which
components are expected to function satisfactorily.
b. Cleaning, Inspection. Parts must be clean to
permit effective inspection for wear or damage. Refer to
Springs must be clean to permit effective inspection.
Section 4, above.
Springs should be replaced if there are signs of
overheating, wear due to rubbing adjacent parts, or
c. Bearings, Bearing Journals, Bores. The
permanent set. Discard springs which do not meet the
application of bearings to any product is based on the
loadheight specifications in the spring chart.
recommendations of the bearing manufacturer and,
therefore, no diametral dimensional deviation should be
WEAR LIMITS CHART
permitted in the bearing or mated parts. Bearings should
be carefully checked for signs of distress before
The chart which follows lists the wear limits data and
reinstalling in the transmission.
is referenced to the exploded views (foldouts 7 through
d. Gears. Gears should be inspected for load
17) in the back of this manual.
pattern and signs of distress. Any distress indicates a
possible future failure, and the reuse of such gears
should be the decision of the individual customer, based
on experience. Backlash cannot be used to establish
Inspection criteria (load vs height) and identification
critical wear of a gear. The backlash tolerances are of
characteristics o f the springs are presented in the spring
such nature that a gear usually pits, scuffs, scores, or
chart following the wear limits chart. The spring data are
galls long before the gear wear becomes critical.
keyed to the exploded views (foldouts 7 through 17) in
the back of this manual.
e. Splines. Unless severe, spline wear is not
considered detrimental except where it affects tightness
of an assembly such as drive line flanges. Here, again,
backlash cannot be used to establish critical wear
Where more than one spring part
because both mating parts must be concentrically
number is listed for the same location,
located to obtain accurate measurement of backlash.
refer to the HT 700 Series Parts Catalog
to determine which spring is used in your
specific assembly number.