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).
The condition of road springs and hydraulic shock dampers.
| Identifier | ExFiles\Box 179\2\ img035 | |
| Date | 1st December 1931 | |
| -3- ROAD SPRINGS Front Road Springs - These were excellently lubricated except for the rear of the right-hand spring which was rather short of oil. There was no appreciable wear on the shackle pins. Rear Road Springs - The rear end of both rear springs had been receiving no oil due to faulty drip plugs. We think that this trouble may have been accelerated by the large capacity in the cross [scratched out] tube before the oil gets to this spring shackle. We are reducing this capacity to see if we can get better results. HYDRAULIC SHOCK DAMPERS. Rear Dampers to F.83611 LOP. - The oil level in both dampers was O.K. The loads on the off-side damper were as set on the near side, the high pressure had dropped by 5 lbs. The oil in these dampers was rather muddy. This is not surprising considering that the dampers have completed the whole mileage without being re-filled. Wear on the split piston pads was .001 on the low pressure side and .0015 on the high pressure side. The main bearing wear was negligible. The cylinder bores had worn approx. .0015. Considering that these dampers have been run at 95 and 110 lbs. and there were no leaks in the high pressure valve, we consider their condition was excellent. Front dampers F.82446 - The main difference between these and the rear dampers was the very dirty condition of the oil. On the near side the filter was almost completely clogged up. The drain plug was nearly full of sludge and there was a liberal amount of dust. The loads when checked on both were approx. 90 and 100 instead of the original 110 and 110. The wrist pin in both cases had worn .001 on the dia. The near side small main shaft ball race was badly worn and there was .002 slack in the housing. Both the ball retaining pins were hammered nearly half way through. This is a fault we invariably find on front dampers and we consider that it requires designers attention. The main difference between the front and rear dampers is the improved cleanliness of those with the cast iron bodies. We note that the front dampers are to be brought outside the frame and we hope that the cases will be similar to those of the rear dampers. | ||