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).
Letter discussing oil leakage issues from rear axle differentials and gearboxes, with proposed solutions.
| Identifier | ExFiles\Box 66\4\ scan0348 | |
| Date | 29th November 1926 | |
| X8350 c/o All British Motor Co.Pty.Ltd., 109-113 Russell Street, MELBOURNE. Pt.6/FP{F. Potts} 29th November, 1926. Hs.{Lord Ernest Hives - Chair}(Derby). Further to my recent letter setting out causes of complaint which have to be met here, I now wish to advise you that we are having very considerable trouble owing to oil from rear axle differential finding its way on to brakes and being flung all over coach work from the brake drums. Cannot something be done to overcome this trouble? We have lowered the oil level in back axle casings one-quarter of an inch, and have done our utmost to prevent the trouble arising, but with very little success. It is most marked on 20 hp. chassis, but occurs to some extent on 40/50 hp. chassis, though to nothing like the same degree as in the former case. I note that in the 40/50 hp. chassis steps have been taken by means of a thrower and baffles to prevent the excess of oil put into the universal joints sphere by over zealous chauffeurs from working down the torque tube and filling up the back axle: but this prevention of leakage from the sphere depends upon rotation of parts, and there is nothing to prevent oil from a sphere over-filled from working down the torque tube to the rear axle when the car is stationary. Another point I would like to take up with you is the nuisance caused by oil leakages from gear boxes - particularly on the 40/50 hp. chassis, and especially when the car is left standing on an incline. Here again the oil seal of the gear box shafts depends upon rotation of parts, and when the engine and car are stationary, there is nothing to prevent leakage when standing on an incline. This could be met by putting the second motion shaft under the first and third motion shafts, instead of alongside them, and I have often wondered why this has not been done. It seems to me that the only way to make a really oil-tight gear box and rear axle is to provide them with a sump containing oil into which the gears did not dip, and to circulate the oil upon the gears which happen to be in mesh by means of a pipe lead from the pump. The ball races could be fed by means of wicks. I think this would effectually prevent oil leakage, and would, moreover, result in a great saving of power now lost in the transmission, by oil churning. Don't you think that an air vent in the rear axle casing might help matters? Pt. | ||