Inspection Of The Shock Absorber
4700 mm 32.01.004
There are many conditions that indicate it may be time to replace shocks. Check for the following conditions.
- Uneven tire wear (check wheel balance first).
- Ride deterioration.
- Excess vibration.
- Sagging taper leaf springs (this is not caused by weak shocks).
- Premature wear on cab, electrical, and cooling system components.
- Broken or torn air springs. Shocks will only affect this if they are broken or missing.
- Upper or lower mount eye broken and dust tube broken. See Fig..
Fig. 1, Shock With Broken Eye and Tube
- Upper or lower bushing cracked or deformed (when not under
load). See Fig..
Fig. 2, Shock With Cracked Bushing
- Bent or dented body. See Fig.. Misting shocks
are often misdiagnosed as failures. Misting is the process whereby
very small amounts of shock fluid evaporate at high operating temperatures.
The mist passes through the upper seal of the shock. When the mist
reaches the cooler outside air it condenses and forms a film on the
outside of the shock body. When mixed with road debris and dust, a
grime will often coat the body of the shock. Misting is perfectly
normal and a necessary function of the shock. The fluid which evaporates
through the upper seal area helps to lubricate and prolong the life
of the seal. Many technicians find it difficult to differentiate between
a misting shock and a true leaker, which needs replacing. A leaker
will show clear signs of fluid leaking in streams from the upper seal.
These streams can most easily be seen when the shock is fully extended
and one inspects as far up the main body of the shock (underneath
the dust cover or tube) as possible. See Fig. and Fig..
Fig. 3, Bent and Dented Shock
Fig. 4, Misting Shock
Fig. 5, Leaking Shock
Note: