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).
Troubleshooting ineffective front shock absorbers and proposed improvements and settings.
| Identifier | ExFiles\Box 68\2\ scan0251 | |
| Date | 7th July 1929 guessed | |
| - 2 - (4) Consequently a prevalent source of trouble, especially on new cars, is "ineffective" front shock absorbers (both old type and axle control) which we find in practically every case is due to excessive leakage caused by cutting of the low pressure valve seat by small flakes of metal, principally aluminum. In some cases the leakage can actually be found to increase perhaps 100% in an intermittent run of a few hours on the bench, and reseating the low pressure valve cures it. The universal symptom of this trouble on the car is an increased tendency to pitch, which is felt only by the rear passengers. We are now doing our utmost to - (1) Improve the cleaning of shock absorbers. (2) Run them on the bench with an "open oil circuit" with a filter in the line to remove dirt. (3) Improve the finish of piston and bore to prevent initial wear. (5) With the slight leakage at the valve we have found it desirable to increase the "poundage" setting on low and high pressure valves, and to use equal up and down poundage on the front instruments, namely :- Front - axle control 120 lbs. up and down. Rear - 60 lbs. up - 120 lbs. down. A recent attempt to use 120 lbs. up and down at the rear appears to be a failure as the low speed riding is too rough. Very truly yours, ROLLS ROYCE OF AMERICA, INC. r/ Maurice Olley | ||