The Gearbox (and Clutch)

The Alvis Clutch and gearbox are separate in the early cars and before 1924 a cone clutch was used. This is the subject of a separate technical article which can be accessed here.

As with everything else, individual components have been lighted, The flywheel and gearbox internals have had metal removed, with a set of straight-cut, lightweight close ratio gears fitted. The gearbox sits on the same subframe as the engine unit, although a shorter Cardan shaft is used because of the rearwards positioning of the engine.

The gearlever is fitted outside the chassis rail on a combined gear/handbrake station as in earlier 10/30 cars and the drive to the rear axle is through a splined Alvis propshaft with massive adjustable universal joints at both gearbox and rear axle ends. A conventional fabric coupling the gearbox and clutch spiders, but no clutch stop is fitted.

The gearbox is a 12/40 four point mounting unit with constant mesh gears on the mainshaft at 19 teeth to 28 on the layshaft in fourth; 22 and 25 respectively in third; 27 and 20 in second and 32 and 15 in first. Top gear gives just under 20 m.p.h. per 1000 r.p.m.

The indirect ratios are 1:1.296; 1:1.99 and 1:3.15