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 testing and failures of various extreme pressure lubricants for rear axles and gearboxes.
| Identifier | ExFiles\Box 145\2\ scan0065 | |
| Date | 29th June 1935 | |
| To E.{Mr Elliott - Chief Engineer} C. to SG.{Arthur F. Sidgreaves - MD} C. to HSR. C. to C. C. to EV.{Ivan Evernden - coachwork} C. to DB.{Donald Bastow - Suspensions} C. to Dr. C. to Eft. C. to Hx. X1231 Ha/Gry.{Shadwell Grylls}2/KR.29.6.35. Extreme Pressure Lubricants. We have to use an extreme pressure lubricant for the hypoid rear axles on the Phantom and Bentley, and also for initial running on 1st speed in Phantom gearboxes. In all these cases Whitmore's compound, made in America, is used. During the past two years we have tried several English lubricants, Wakefield's Gearease, a copy of Whitmore's, was not altogether satisfactory judging by a few Phantom axle failures. On Bentley chassis we tried both Mobiloil and Wakefield's "E.P." oils. The latter underwent modification after our first run. Both the original E.P. oils caused deposits of black sludge in the axle casing sufficient to silt up the oil ways, preventing adequate lubrication of the bearings. About this time we started having failures of the Bentley rear axle pinion thrust race. During the tests carried out by Ransome & Marles in evolving a satisfactory race, they ran tests on Wakefield's second "E.P." oil, Whitmore's and Duckham's "Keenolised" oil. During the runs on all these oils hard carbon deposits formed in the bearings, completely obstructing the oil ways after about 70 hours and in certain cases the deposit built up on the shoulders of the inner race, causing failure of the cage. Runs on Whitmore's compound showed a certain amount of deposit, but in no way comparable with E.P. oils. We consulted Wakefield's about this trouble and they produced their new "Hi-Press" oil. After a run of 380 hours at 4,500 r.p.m., very little deposit had formed and what there was was not of a hard nature. The deposit was not so great as with Whitmore's compound. | ||