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).
Outstanding complaints for the Bentley 4¼ Litre chassis, focusing on rear axle and engine bearing issues.
| Identifier | ExFiles\Box 107\2\ scan0218 | |
| Date | 4th February 1936 | |
| SG.{Arthur F. Sidgreaves - MD} Hs.{Lord Ernest Hives - Chair} BY.{R.W. Bailey - Chief Engineer} RM.{William Robotham - Chief Engineer} C. EX. H.{Arthur M. Hanbury - Head Complaints} Rm{William Robotham - Chief Engineer}/CWH.15/G.4.2.36. BENTLEY. The following are the outstanding complaints on the Bentley chassis - 4¼ Litre :- REAR AXLE. The rear axle is the outstanding weakness of the Bentley. Considerable trouble is experienced with the trunnion bearing. To keep the axle quiet is a tool room job. The thrust races have to be preloaded to a fine limit, also a fine limit nip of the housing is necessary. The thrust race Ch.2035 is now superseded by a slightly larger race Ch.2680. During the last month there has been an epidemic of the thrust race cages breaking. Where the cages have not been broken, balls have been found chipped. 63 driving dogs have been changed during the last three months for owner complaints of rattle. The modified driving dogs have so far been free from rattle - due care is being taken to well lubricate them during assembly. Loss of oil from the nose piece has resulted in a scrapped crown and bevel gear. The Paris Depot do not have to deal with these complaints to the extent we do here, due solely to the fact that the French owners are not so critical. ENGINE BEARINGS. The mileage of the cars have brought the trouble with bearings prominent. In England the average is approximately 27,000 miles. At this stage it has been found the better policy to carry out the full modification to crankshaft and bearings. In most cases this modification is done in conjunction with the bottom decarb, thus allaying heavy expenses. On the Continent it is an entirely different proposition. The stage of reconditioning the bearings comes at an average of 40,000 miles. At this mileage it would be too expensive to carry out the full modification, and they are able to temporarily adjust the bearings with the assistance of the large oil pump to carry on until the mileage has reached the stage of the bottom decarb. This is possible due to the fact that the French Owner does not criticise the roughness of the engine, where an average English owner would not tolerate it. | ||