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).
Technical explanation on the causes of troubles in coachwork due to body settling and chassis twist.
| Identifier | ExFiles\Box 125\1\ scan0153 | |
| Date | 23th January 1935 | |
| CWW/MO. 23rd January, 1935. CAUSES OF TROUBLES IN COACHWORK. As explained to Mr. Evernden, it is most essential that after a car has done a few hundred miles, the body be rebedded to the chassis. If this procedure is not adopted it may lead to very serious complications. In the first instance the body is built on an absolutely square rectangular Horse or Frame, this Frame standing on a level floor, hence the bottom sides and all upright pillars are making correct right angles one with the other. Consequently, all other battens and cross members are fitted at the correct tension all through. After the car has been driven a certain distance, a slight variation in the settling down of the road springs, also the body packing bedding themselves down make it a necessity to adjust the body as stated above. We will assume during test or first running, the nearside front spring settled down ¼", the offside rear does not settle down - there is immediately a slight twist on the chassis. It is the rectification of the body seatings to overcome this twist that we have to adjust. We have found by experience, that where a front door has dropped approximately ⅛", it has only been necessary to insert a piece of packing between the body bracket and the bottom side of barely 1/32" to overcome this trouble. From this it will appear apparent that, should the body be run in this semi-twisted condition, one is getting adverse strains on the different pillars and battens of the body, some in compression, others in tension. We have also found that it is this settling down of the front springs that causes screen rattles and leakage. (The screen, especially those which open) are made with as small a gap as possible and again made and fitted to the body whilst it is in its correct position. The opening for the screen is made a perfect rectangle. The front of the body develops a twist and immediately this rectangle becomes distorted allowing one side of the screen to touch the pillar and cause a | ||