8516 x 1. XK150 EARLY Rev. Counter Drive Shaft which unlike the XK120 & 140 screws into the end of the INLET Camshaft, for the XK150 clockwise rotating Rev. Counter gauge (Tachometer).

(XK120 & XK140 Tachometers run anti-clockwise, off the exhaust cam).

This drive connector is the earlier, direct mechanical system, so directly couples to the angle drive box, SEE : 8523 which sits on an angular adaptor plate (which rotates it) SEE :  8523A  and then in turn drives the 17" mechanical cable at the correct angle to the gauge, SEE : 5940

NOTE : This early assembly is listed, but not illustrated in the Jaguar XK150 Parts book, they only show the later electric drive rev. counter system.

Original Ref. Number C10665