TRUCK SERVICE MANUAL
SPRINGS
DESCRIPTION
SERVICING
Constant Rate
Although the exact servicing procedures are different
for each type of spring assembly and spring assembly
Constant rate springs are leaf-type spring
application, the basic procedures are similar. The
assemblies that have a constant rate of deflection. For
following is a general out line for servicing all spring
example, if 500 lbs. deflect the spring assembly 1 inch,
assemblies used on IH vehicles.
then 1000 lbs. would deflect the same spring assembly
Removal
2 inches. Thus, the rate of deflection is constant.
1. Place floor jack under truck frame and raise truck
Constant rate springs are mounted to the axle with
sufficiently to relieve weight from spring to be
U-bolts, nuts and lockwashers. The front end of the
removed.
spring is mounted to a stationary bracket while the rear
end of the spring is mounted to a spring shackle. The
2. Remove shock absorbers where used.
shackle allows for variations in spring length during
compression and rebound of the spring.
This type of spring assembly is used in both front
and rear applications on IH vehicles.
Spring Shackles (Figs. 7 allow for
variations in spring length during compression
and rebound of spring. Shackles pivot on either
lubricated spring bracket pins
Spring Bracket or Shackle Pins used on IHI
trucks will be one of the following three types.
2. Pins that are driven into shackles or
brackets.
Fig. 7 Lubricated Spring Shackle (Driven-in
type spring pin).
TORQUE CHART
FOR ASSEMBLY OF SUSPENSION U-BOLTS
ROLLED THREAD U-BOLTS
7/8"-14
225 - 275
1" -14
325 - 400
NOTE: When servicing suspension assemblies, all U-
bolts must be thoroughly cleaned and lubricated
with Tectyl 400-CWD or equivalent before
reassembly.
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