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).
Review of the advantages and disadvantages of the Packard suspension system.
| Identifier | ExFiles\Box 154a\2\ scan0054 | |
| Date | 27th March 1939 guessed | |
| -2- What are our views on those advantages of the Packard suspension today:- (1) The ride of B.5. we are told is good, but only just sufficient wheel movement is available for the present rating. (2) The rubber bearings do reduce noise, but we still have to have the body completely isolated from the frame on soft Floatex bushes as on Wraith III and Phantom III. (3) The torque arm reaction is very small and has little effect on the diving resulting from braking. (4) Rubber joints have reduced the lubrication difficulties, but have introduced the more frequent servicing changes of about 50,000 miles. (5) The spread lower triangle gives no greater ease of forward engine position than does the wishbone, torsion bar, or Dubonnet. The two disadvantages (a) and (b) still hold good. No other firm has taken up the design, at home or abroad, and the pieces are still ugly and heavy. The following new disadvantages appear to have manifested themselves. (A) The rubber bearings have a rating of approx. 23 lbs. per inch at the wheel, which appears gradually with age. dis (B) The bent coil spring gives an increased rating above the theoretical figure. (C) The car wanders at high speeds, and this we suggest may be due to the rubber bearings of the lower triangle levers deflecting radially and increasing the track. Due to the fixed cross steering tube length this would alter the toe-in, and may account for certain troubles such as variations in toe-in, joggles on steering wheel on corners, and peculiar tyre wear. Ten thous. on the bearing represents 1/12° on the road wheel. Cont'd...... | ||