May 1978
DUMP BODY HOIST CYLINDER SHIMS
1. A user of the CCE-IHC, 20-ton 6x4 Dump Truck has submitted an EIR suggesting the use of shims on the hoist
cylinder packings, like the commercial users do, to prevent the heavy leakage of the packings. The use of shims with the
packing cannot be recommended. The leakage of oil from around the packings of the hoist cylinder stages is normal and
is necessary to self-clean the cylinder from contamination and to prevent rust. Any cost savings attributable to use of
shims, in lieu of waiting for replacement with new packing, will be grossly overshadowed by the higher cost of new
cylinders. Overtight packing caused by shim adjustment will cause cylinder rust, wear, and scoring. Overtight packing will
also contribute to binding of the hoist in the raised-dump-body position.
2. Shims are being made available for those knowledgeable users who have the know-how and the need to retard hoist
cylinder packings oil flow. Shims must never be employed by users to prevent "truck inspection gigs resulting from hoist
cylinder leakage".
3. The shims should be made available for abnormal circumstances where wear or other hoist cylinder problems cause
the normal packing to malfunction on one or more telescopic stages. Under these circumstances, the shims may prevent
cylinder replacement and should be authorized for local procurement based on the advice of knowledgeable personnel,
military or commercial.
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