Most of these trucks are equipped with hydraulic shock absorbers as standard equipment. Some, however, are equipped with low pressure gas shock absorbers as standard equipment and all are available with gas shocks as optional equipment.
REMOVAL & INSTALLATION
Remove the self-locking nut, steel washer, and rubber bushings at the upper end of the shock absorber. Remove the bolt and nut at the lower end and remove the shock absorber.
When installing a new shock absorber, use new rubber bushings. Position the shock absorber on the mounting brackets with the stud end at the top.
Install the rubber bushing, steel washer and self-locking nut at the upper end, and the bolt and nut at the lower end. Tighten the upper end to 25-35 ft. lbs. (34-47 Nm) and the lower end to 40-60 ft. lbs. (54-81 Nm).
TESTING AND INSPECTION
Each shock absorber can be tested by bouncing the corner of the truck until maximum up and down movement is obtained. Let go of the truck. It should stop bouncing in 1-2 bounces. If not, the shock should be inspected for damage and possibly replaced.Inspect the Shock Mounts
Check the shock mountings for worn or defective grommets, loose mounting nuts, interference or missing bump stops. If no apparent defects are noted, continue testing.Inspecting Hydraulic Shocks for Leaks
Disconnect each shock lower mount and pull down on the shock until it is fully extended. inspect for leaks in the seal area. Shock absorber fluid is very thin and has a characteristic odor and dark brown color. Don't confuse the glossy paint on some shocks with leaking fluid. A slight trace of fluid is a normal condition; they are designed to seep a certain amount of fluid past the seals for lubrication. If you are in doubt as to whether the fluid on the shock is coming from the shock itself or from some other source, wipe the seal area clean and manually operate the shock (see the following procedure). Fluid will appear if the unit is leaking.Manually Operating the Shocks
It may be necessary to fabricate a holding fixture for certain types of shock absorbers. If a suspected problem is in the front shocks, disconnect both front shock lower mountings.
When manually operating air shocks, the air line must be disconnected at the shock.
Grip the lower end of the shock and pull down (rebound stroke) and then push up (compression stroke). The control arms will limit the movement of front shocks during the compression stroke. Compare the rebound resistance of both shocks and compare the compression resistance. Usually any shock showing a noticeable difference will be the one at fault.
If the shock has internal noises, extend the shock fully then exert an extra pull. If a small additional movement is felt, this usually means a loose piston and the shock should be replaced. Other noises that are cause for replacing shocks are a squeal after a full stroke in both directions, a clicking noise on fast reverse and a lag at reversal near mid-stroke.