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).
Clutch and flywheel performance issues with 'No.6 Material' and subsequent modifications.
| Identifier | ExFiles\Box 91\1\ scan0394 | |
| Date | 14th June 1936 | |
| -9- 109/9 Clutch & Flywheel. LOP.C. 84357 N.Sch. 4738/4747. No.6 Material The clutch when received was found to be quite fair and until really hot did not jagger. It got progressively worse and it was hard to engage any gear from neutral without first tipping the synchro. On 14.6.36. i.e. after having completed 5,600 miles, a new clutch plate was fitted with a thicker fabric. The old fabric was considerably torn up and broken, the rivets having dug in sideways, allowing the fabric to move. Large bits of fabric had become dislodged and had fused on to the flywheel face. A thicker fabric with a larger surface area for rivet heads was therefore fitted. This jaggered at the outset, and continued to do so for the remainder of the mileage, although we made sure that the fingers were set correctly. We are of the opinion that the set up of the plate segments does not take effect, by reason of the thickness of the fabrics. This cuts out any sensitiveness the clutch may have and causes jaggers. Further modification will be necessary before a good clutch can be produced. The clutch plate was slow to stop and made it difficult to engage any gears from stationary, and this must have also had an effect upon the working of the synchromesh which was poor at all times. On fitting the second plate we made certain that it was free on the splines, so as to ensure that it should free correctly. No undue wear took place which necessitated the re-adjustment of the foot pedal. Removal of the clutch housing was made difficulty it being impossible to withdraw the set screws unless the engine was dropped onto its back rests so as to bring the studs in line with the holes in the cross member. It was suggested that we cut suitable holes to accommodate the studs, which no doubt would have made things easier. We noticed that the needle roller bearings, which mount the trunnion cross shaft, had dug into the shaft, obviously making the shaft uneven to work under load. It appeared that the shaft was made of soft material and was not able to withstand the pressure. | ||