From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Investigations into complaints regarding hydraulic shock dampers on 20 HP and Phantom models.
| Identifier | ExFiles\Box 47\2\ Scan399 | |
| Date | 21th November 1930 | |
| To Wor.{Arthur Wormald - General Works Manager} from Hs{Lord Ernest Hives - Chair}/GWH.{George W. Hancock - Head Chateauroux} c. Hs.{Lord Ernest Hives - Chair} X4117. Hs{Lord Ernest Hives - Chair}/GWH{George W. Hancock - Head Chateauroux}1/AD21.11.30. The following complaints have been dealt with during my visit to Cricklewood :- Hydraulic Shock Dampers. We have, during the investigation of these complaints, found out the mysterious cause of the knocks on the 20 HP. dampers, rear and front. These knocks are caused by the hydraulic hammering of the air release ball in the high pressure cap, and by limiting the movement of the ball we entirely eliminated the knock, heard and felt on the car. One other feature which is a frequent cause of knocks is the stoppage of the air vent by flakes of aluminium and fluff; this stoppage has been found in most cases. A filter is being tried out by Rm.{William Robotham - Chief Engineer} to prevent this failure. The dampers dealt with are as follows :- 20 HP GYL-52 Rear dampers. Knock caused by ball. GBM-7 " " -do- GGP-24 " " -do- GSR-78 " " -do- GVO-47 O.S.R. " Also vent holes stopped up. GEN-55 N.S.R. " -do- GAJ-8 N.S. front Gudgeon pins worn. Failure of poundage, due to dirt under low pressure valve. Phantom XJ-141 O.S. Rear Air vent stopped up. Made O.K. XJ-102 O.S. Front Bronze bush fitted to lever. XJ-44 N.S. " Dirt in vent hole. XJ-87 O.S. " Sphere in piston found to be tight; signs of seizing. XJ-178 N & O.S. front. Sphere in piston found tight in O.S; bronze bushes fitted to both levers to eliminate wear. GN-142 N & O.S. front. Poundage increased to 100 for steadiness of steering. GN-1 N & O.S. rear. Ventilation hole to stop dampers losing oil. XJ-162 O.S. front Gudgeon pin worn, new pin and bush fitted. | ||