152 Auto Suspension and Steering
Replacing MacPherson Struts and Shock
Absorbers
Shock absorbers and MacPherson struts used on the
rear suspension are similar in design and operation to those
used on front suspensions. Replacement operations are
also similar.
MacPherson Strut Replacement
MacPherson struts used on rear suspensions are
essentially the same as those used on front suspensions.
Replacement procedures are also similar. On many
vehicles, the strut mountings are located inside the trunk.
See Figure 8-8. Some trunks have carpeted interiors, and
the carpet must be pulled back to access the strut top studs
and nuts. Most rear strut tops have two studs.
The strut mountings can also be located under the
back of the rear seat, or under a trim cover (on hatchback
bodies). In these arrangements, the seat or trim covers must
be removed to gain access to the upper strut fasteners.
After disconnecting the top of the strut, remove the
wheel to gain access to the bottom of the strut. Remove
any brake hoses that may be mounted on the strut body.
Then remove the fasteners holding the lower end of the
strut to the spindle, Figure 8-9. Remove the strut from the
vehicle. Figure 8-10 shows typical upper and lower strut
installation. It may be necessary to push down on the
spindle to gain enough clearance to remove the strut from
the lower mounting.
To disassemble the strut, place it in a strut compressor.
This was discussed in Chapter 6. Mark the relationship of
the spring, upper mount, and strut; then compress the strut
spring. Remove the top nut from the strut and remove the
cartridge.
Check all parts for damage and replace damaged
components as necessary. Reassemble the new strut to the
spring and reinstall the assembly on the vehicle.
Shock Absorber Replacement
There is usually sufficient room around rear shock
absorbers to easily reach the fasteners. However, the
exhaust system parts must be allowed to cool before
working near them. Rear shock absorbers commonly use
large mounting studs, Figure 8-11. Some shock absorbers
have a large stud mounting at the bottom and the top is
held by nuts and bolts, Figure 8-12.
Upper
strut
mounting
Figure 8-8. This strut mounting is located in the trunk
compartment.
Spindle
Strut
Bolt
Strut
Nuts
Spindle
Bolts
Figure 8-9. One type of rear strut assembly mounted in the
spindle and secured with a bolt. (General Motors)
Figure 8-10. This rear strut illustration shows upper and lower
mountings. Note that the lower mounting is secured with two
bolts. (General Motors)