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).
Technical memorandum discussing issues with shock absorbers, body noise, connecting tubes, and damper oil.
| Identifier | ExFiles\Box 55\4\ Scan316 | |
| Date | 23th February 1929 guessed | |
| - 2 - (5) Note Rm{William Robotham - Chief Engineer}'s. suggestion to use links in "nitro-steel." I am asking him whether he does not refer to "Nitralloy" pins. I think we have no experience of wear in the pins or the side faces of the links. "External" causes. Please note Rm{William Robotham - Chief Engineer}'s analysis of causes external to the shock absorbers themselves:- (1) Body construction and mounting. Undoubtedly our coachwork is very "sound and often a very good" sounding box. It is strange that Derby have trouble chiefly with rear shock absorbers on the 20 hp. We had rear shock absorber clicks before fitting drilled valves, but our troubles now seem to be entirely in the front dampers. Our steel mudguards may contribute to this. Derby until just recently have used the separated dash and even now use a separated scheme with rubber buffers. Our more solid rubber joint may increase sounds from the front. (a) The "silencing pad" on the dash should therefore help to reduce complaints. (b) It suggests also that careful inspection of adjustment and lubrication of the connecting tubes is desirable. (c) Also in some cases the front bumper may be the real cause of the knock. (d) Properly "insulated" floorboards are essential we know to reduce noise in the body. (2) Connecting Tube. I propose that we should wait for England to send us drawings of a spring loaded tube. With chassis lubrication and properly fitted bronze pads the present solid tube should hold its adjustment indefinitely. Judging from experimental work the present tubes if they are fitted and adjusted right in the first place are satisfactory. (3) Oil. We still have to discover a satisfactory oil for filling the shock absorbers. The Vacuum Company are working on this but have not yet reported. On 318-FM we have 80% glycerine 20% alcoho, which must now have run some distance. Will Mr. Ainsworth inspect these dampers and report results? We should prefer a real lubricant. -continued- | ||