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).
Issues with front springs, clutch, and gearbox components during testing.
| Identifier | ExFiles\Box 4\9\ 09-page017 | |
| Date | 10th June 1925 | |
| R.R. 498a (Rev) (D.B. 17) 25-9-34) J.M.D. EXPERIMENTAL REPORT -3- Expl. No. REF:GWH{George W. Hancock - Head Chateauroux}1/Crn10.6.25. Front springs (Firths) F.53332 - 12¼% springs (stronger) 600 and 650 lbs. N.S. spring top leaf broke after 2,750 miles approx. The fracture was clean. There did not appear to be any flaw in the steel. The breakage is 10" rear of centre bolt. Condition of other leaves of springs - sound. O.S. spring taken down and examined - all leaves are O.K. but we notice that the bedding of the leaves is very poor. At either end the leaves have dug in. We also noticed that all the leaves are curved, which throws the bedding on the centre at one side, and on the outer edge on the other side. This applies to both springs. As reported the front springs were continually hitting the buffers. The roads over here are in a very poor condition generally, and the test for springing is a very severe one. CLUTCH. On one run it was inclined to be on the fierce side, but generally it has been smooth in action and we have no jaggers. We have no trouble with the clutch not stopping when depressed. GEARBOX. We have had a bad oil leak from covers at front and rear of the box. We have dismantled these and found at the front that two studs have not been screwed down sufficiently. Consequently, the shoulders on same were not allowing the cover G.51595 to seat properly. We have recessed the holes for these bolts. We also found that the ball race Hoff.330 on the 2nd. motion shaft stands slightly proud of the face, and also the reverse shaft containing sleeve G.51582 was also standing slightly proud. We have fitted a paper packing washer to allow for the discrepancies, and will report later whether this has cured the oil leak. The leak from the rear cover G.51592 was due to a slight burr on the surface. We consider that the spring for the reverse plunger in change speed lever could be of less strength, also we would recommend that plunger top be slightly more spherical, as one can feel the sharp edge in the palm of the hand. As reported and questioned, the changing of gears is not so easy as in the standard 20 HP. We do not condemn the change speed mechanism. We get the same effect but in a lesser degree than we got on the R.M.C. of the same design, i.e. if one tends to pull the lever backwards in changing, there is a binding effect. On the other hand, if the lever is pushed sideways evenly, the change is quite easy. The gears are fair. We have not had any gears work out up to the present. The reverse gear has functioned O.K. but one can feel when depressing the foot pedal the action of the servo plates, as if they were not running quite true. We get a slight rattle from servo gears on overrun from 43 m.p.h. to 35 m.p.h. There is no measureable wear on these gears. The servo mechanism is quite O.K. We believe that new cams are being sent out to lessen the tendency of fierce braking. contd :- | ||