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).
Investigation into the cause of noisy rear shock dampers on a 20 HP car following a customer complaint.
| Identifier | ExFiles\Box 47\5\ Scan221 | |
| Date | 13th December 1928 | |
| To Wor. {Arthur Wormald - General Works Manager} To Hm. {Capt. W. Hallam - Head Repairs} c. to Mx. {John H Maddocks - Chief Proving Officer} c. to BY. {R.W. Bailey - Chief Engineer} from Hs {Lord Ernest Hives - Chair} /Rn. {Mr Robinson} V418 Hs {Lord Ernest Hives - Chair} /Rn {Mr Robinson} 7/LG13.12.28. 20 HP. REAR SHOCK DAMPERS. X5520 In pursuance of our investigation of 20 HP. rear shock damper knocks we investigated the complaint of Mr. Blackmore's GBM.21. His rear shock absorbers were found to be very noisy. Experimental pieces which can easily be fitted to the dampers were tried but did not remedy the trouble. His shock absorbers were then dismantled and it was found that lever F.74896 was fouling piston F.74879 badly at each end of the stroke at points A-A. {Mr Adams} This occurred because the core which determines the position of points A-A was not central in the piston. The drg. limits do not prevent the possibility of such a piston being fitted, but the limits have been altered now that the point is appreciated. We suggest that similar trouble may be suspected in cases of complaint. We consider that the shock absorbers might have become noisy had the lever not fouled the piston in the manner described, but that this trouble would undoubtedly strain the linkage and accelerate wear. Owing to the owner requiring the car we were not able to complete our investigations; his complaint was cured by fitting a pair of untouched standard dampers off production. The only precaution we took was to ascertain that contd :- | ||