A shock absorber assembly including: a motion damping means that is filled with a fluid in operation and has a pair of relatively movable parts (12, 14; 112, 114) and valve means permitting flow of said fluid between said parts, said parts comprising a first part (12; 112) and a second part (14; 114) in which the first part is receivable whereby the parts are arranged for relative retracting and extending movement during which fluid is forced through said valve means at respective predetermined controlled flow rates so as to dampen said movement; wherein said relatively movable parts contain respective primary chambers (24, 29; 124, 129) for said fluid and said first part is substantially smaller in cross-section than said second part to define an intermediate chamber (52; 152) about the first part within the second part; and wherein there is further included lateral port means (56; 156) communicating between said intermediate chamber (52; 152) and said primary chamber (24; 124) of the first part (12 112); characterised in that said valve means includes respective shim packs (54, 55; 154, 155) and said flows at respective predetermined controlled flow rates in part controlled by said shim packs are limited to respective flows: (i) directly from the primary chamber (29; 129) of the second part (14; 114) to the intermediate chamber (52; 152) via an outer ring of compression ports (50; 150) in said valve means and a respective non-return shim pack (54; 154) during the retracting movement; and (ii) from said intermediate chamber (52; 152) to the primary chamber (29; 129) of the second part (14; 114) via the lateral port means (56; 156), the primary chamber (24; 124) of the first part (12; 112,) at least one rebound port (40; 140) which is radially separated from the outer ring of compression ports (50; 150) and a respective non-return shim pack (55; 155) during the extending movement; such that said respective predetermined controlled flow rates in the respective directions via said compression and rebound ports (50, 40; 150, 140), are different whereby to vary the damping characteristics according to whether said movement is relative retracting or extending movement. a motion damping means that is filled with a fluid in operation and has a pair of relatively movable parts (12, 14; 112, 114) and valve means permitting flow of said fluid between said parts, said parts comprising a first part (12; 112) and a second part (14; 114) in which the first part is receivable whereby the parts are arranged for relative retracting and extending movement during which fluid is forced through said valve means at respective predetermined controlled flow rates so as to dampen said movement; wherein said relatively movable parts contain respective primary chambers (24, 29; 124, 129) for said fluid and said first part is substantially smaller in cross-section than said second part to define an intermediate chamber (52; 152) about the first part within the second part; and wherein there is further included lateral port means (56; 156) communicating between said intermediate chamber (52; 152) and said primary chamber (24; 124) of the first part (12 112); characterised in that said valve means includes respective shim packs (54, 55; 154, 155) and said flows at respective predetermined controlled flow rates in part controlled by said shim packs are limited to respective flows: (i) directly from the primary chamber (29; 129) of the second part (14; 114) to the intermediate chamber (52; 152) via an outer ring of compression ports (50; 150) in said valve means and a respective non-return shim pack (54; 154) during the retracting movement; and (ii) from said intermediate chamber (52; 152) to the primary chamber (29; 129) of the second part (14; 114) via the lateral port means (56; 156), the primary chamber (24; 124) of the first part (12; 112,) at least one rebound port (40; 140) which is radially separated from the outer ring of compression ports (50; 150) and a respective non-return shim pack (55; 155) during the extending movement; (i) directly from the primary chamber (29; 129) of the second part (14; 114) to the intermediate chamber (52; 152) via an outer ring of compression ports (50; 150) in said valve means and a respective non-return shim pack (54; 154) during the retracting movement; and (ii) from said intermediate chamber (52; 152) to the primary chamber (29; 129) of the second part (14; 114) via the lateral port means (56; 156), the primary chamber (24; 124) of the first part (12; 112,) at least one rebound port (40; 140) which is radially separated from the outer ring of compression ports (50; 150) and a respective non-return shim pack (55; 155) during the extending movement; such that said respective predetermined controlled flow rates in the respective directions via said compression and rebound ports (50, 40; 150, 140), are different whereby to vary the damping characteristics according to whether said movement is relative retracting or extending movement.