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).
Test report number 11 on the Cone Clutch Type Servo for the 99-MK car, detailing troubles, mileage, and remedies.
| Identifier | Morton\M20.3\ img039 | |
| Date | 25th September 1924 | |
| SHEET 3. CONE CLUTCH TYPE SERVO - 99-MK CAR. TEST NO. 11 TABLE: TROUBLES: Throttle governor seized up. Front brakes jagger. Brake equal. Action remains constant but servo efficiency varies very considerably owing to oil on servo liner. Dynamo inaccessible for examination. Steering arm bolts stretched on two occasions and one bolt broke. A.T. speedometer - mileage indicator not working. Oil leaks from bottom of pivots. Exhaust throttle seizing up. Rear shock absorber bracket on axle broken. 3 exhaust valves burnt out. A.T. speedometer failed. Spare wheel carrier broken. Windscreen broken. MILEAGE: 1400 Shocker (handwritten) (blank) 5200, 7907 2000 (blank) (blank) 5221 5321 10176 (blank) (blank) CAUSE OR REMEDY: Old type front axle and side steering tube springs. New axle fitted later and new springs much improved steering. Jaggering overcome on later cars. Servo system discarded - this was the only one of its type tested. Rectified in later designs. Bolts made larger in dia. in later design. Driving pinion - several teeth broken. Later axle design overcame this trouble. Exhaust system re-designed. Design of bracket modified. Use of silicochrome steel flat topped valves on later cars proved successful. Returned to makers. Coachbuilders design. (blank) TOTAL MILEAGE OF TEST - 9,449. EXPERIMENTAL REPORT REF: Expl. No. R.R. 493A (50H) (D.B. 175 25-9-24) J.H.D. | ||