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).
Two modifications to hydraulic shock absorbers to reduce knocking.
| Identifier | ExFiles\Box 16\5\ Scan033 | |
| Date | 1st November 1931 | |
| To Hd.{Mr Hayward/Mr Huddy} (For Depot Sheet) HS{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}1/ADL1.11.31. HYDRAULIC SHOCK ABSORBERS. X.235. X.7520. X.5520. "Recently, two modifications have been incorporated on hydraulic shock absorbers which materially reduce the tendency to knocks. Both these modifications can be applied to existing shock absorbers without serious difficulty. The modification to the rear shock absorber is to insert a small steel seat in the replenishing ball valve holes, having previously drilled these out as per attached sketch F.83922. It is essential that these small steel pieces should be put in as a good fit to ensure that no leakage occurs up the threads. The modification to the front shock absorber is a pipe which runs from the air vent over the top pin joint thereby ensuring that no matter how low the level of the oil falls in the shock absorber an adequate supply of lubricant is always supplied to this vital point. N.Sch.3244. Care should be taken that the rivets are a good fit and that the pipe is clear of the lever in all positions. We think that whenever customers shock absorbers give trouble from - (1) Knocks in the pin joint on the front shock absorbers. (2) Knocks on the rear shock absorbers due to the replenishing valves having sunk into their seats. these two modifications should, as a matter of course, be carried out. It is no use re-cutting the aluminium seat of the replenishing valve or fitting new pin joints in the front damper without the pipe, if this is done the customer will only return with his trouble in a short time. HS{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||