160 Auto Suspension and Steering
housing. To remove the spring, raise the vehicle and
remove the rear wheels for clearance. Install a large
C-clamp about 9 inches (230mm) from one end of the
spring. The C-clamp will hold the spring together as it is
removed.
Note: Newer versions of this suspension
use a single fiberglass-composite leaf, and
the C-clamp is not needed.
After installing the C-clamp, place a jack stand under
the vehicle and push the spring upward, Figure 8-32. This
will release the spring tension on the spring link. Loosen
the link fasteners and remove the link. Then lower the
jack stand and allow the spring end to hang. Repeat the
procedure to remove the spring link from the other side of
the spring.
After both spring links have been removed, remove
the bolts holding the spring clamp plate to the axle
housing or differential carrier. With the bolts removed,
remove the plate and remove the spring from the vehicle.
It may be necessary to slide the spring out horizontally to
clear the exhaust system components.
To install the new spring, slide it into position and
install the spring clamp plate. Then raise one side of the
spring using a jack stand and reconnect the spring link.
Finally, install the spring link on the other side of the
spring.
Adding Helper Springs
To increase the load-carrying capacity of the vehicle,
helper springs are sometimes installed. There are two types
of leaf spring helpers: the auxiliary leaf spring and the coil
spring. The auxiliary leaf spring is an extra leaf spring that
is installed on the original leaf spring assembly using clips
or U-bolts. The extra tension of the auxiliary leaf
spring allows the vehicle to operate with heavier loads.
Figure 8-33 shows some common leaf-type helper springs.
Some leaf spring helpers are small coil springs that are
installed between the center of the leaf spring and the
bottom of the frame. To install these helper springs on a
leaf spring rear suspension, raise the vehicle by the frame,
allowing the rear axle to hang. Then place the helper
spring in position and tighten the mounting fasteners. It is
not necessary to remove the leaf spring to install these
helper springs.
There are two basic kinds of coil spring helpers: the
variable-rate spring (sometimes called a cargo spring or
cargo coil), and the air bag. To install a variable rate spring,
follow conventional spring replacement procedures. To
install an air bag, raise the vehicle and allow the rear
Spring compressing tool
Transverse
spring
Figure 8-31. Moving the transverse spring sideways for easy
removal. (General Motors)
Leaf
spring
Wood
block
C-clamp
Spring
link
Jack stand
Use a wood block as
shown to protect
fiberglass spring
Figure 8-32. Jack stand is used to push upward on the spring
to loosen the spring link. Note the use of wood blocks to protect
the spring. (Chevrolet)
U-bolt
Auxiliary spring
Spacer
Frame
rail
Pivot
bracket
Front
Locknut
Washer
Spring bracket
Axle tube
Bracket
Bolt
Pad
Pivot
bracket
Nut
Leaf
spring
U-bolt plate
Figure 8-33. This rear pickup truck leaf spring suspension
incorporates a helper, or auxiliary, spring. (Dodge)