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).
Owners complaint report investigating the failure of a Fabroid idler gear on chassis 3.AX-153.
| Identifier | ExFiles\Box 96\1\ scan0391 | |
| Date | 19th May 1939 | |
| W/S-C c. to Hd.{Mr Hayward/Mr Huddy} c. to Rm.{William Robotham - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} c. to Mx.{John H Maddocks - Chief Proving Officer} c. to GWH{George W. Hancock - Head Chateauroux} (K) 361 Files BY/SB.{Mr Bull/Mr Bannister}4/MG.19.5.39 CHASSIS NO. 3.AX-153. Prof. Lambert Rogers Owners Complaint Report No. W.343 This car broke down in service due to failure of the Fabroid idler gear which transmits the drive from the crank pinion to the camshaft wheel and auxiliaries. Eleven teeth had stripped off, thus putting the camshaft and distributors out of commission. Careful examination has been made of the engine to find the cause, but there is no definite evidence to prove what has occurred. The failure could have been due to either:- (a) Seizure of one of the auxiliary drives, which would put a heavy load on the idler gear. This can be ruled out because the dynamo drive, distributor cross shaft, water pump, camshaft and idler bearings have all been examined and there is absolutely no sign of seizure. (b) Wear of the idler teeth to such an extent that the section of the tooth is weakened to the point where its mechanical strength is insufficient. This is problematical, as we have plenty of Phantom IIIs in service which have done 3 or 4 times the mileage of this car, and the wear on the teeth is as much as .025" without causing any trouble other than gear rattle. (c) A faulty gear. This seems the most probable explanation, and is supported by several other factors. The sequence of events seems to be, firstly, a small section of three teeth pulled out, this being evidenced by the carbonised appearance of the fracture at this point indicating that this occurred some little time ago. Secondly, these pieces (continued) | ||