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 performance and issues with front brakes, cross steering tubes, and the rear axle.
| Identifier | ExFiles\Box 108\1\ scan0197 | |
| Date | 10th September 1937 | |
| 9. Front Brakes LOP.GW.1612 Front Hubs LOP.GW.1588 O.F.830 aluminium brake drums. Brakes lined with Ferodo MZ. The O.S. front brake was thoroughly satisfactory in every way and withstood some very severe testing. The adjustment used up showed that it was doing its calculated share of the work relative to the rear brakes. The N.S. front brake was, for some reason not satisfactorily explained, doing approximately twice as much work as was intended. During a severe test down a long mountain pass this drum became badly over-heated and the liner cracked at two of the four locating keys. It became displaced laterally in the drum although it did not come loose or turn. The brake efficiency was not seriously effected, the only intimation of the failure being the projecting portion of the liner rubbing against the carrier plate. These liners were originally made for eight locating keys, which are now to be fitted, and might have prevented this failure. The present programme however, specifies iron front drums for production since they are twice as highly stressed as the rear drums. Squeaks were experienced throughout the running. Cross Steering Tubes LOP.GW.1565. No trouble was experienced and high loading on the joints was not required as on Phantom III, as no wheel wobbles occurred. Rear Axle LOP.GW.1475. Continual small oil leaks occured from the breather hole on the centre casing. Slight leaks occured from the flanges. The axle gave no trouble. A very slight uneven hum was audible on the over-run at 40.M.P.H. The cause is not known, but comparative tests with a propellor shaft damper fitted have been asked for. | ||