Final drive ratio help

[RootesRacer]

Then why did mine break? I did none of the above, switches were fine, quit at about 30,000 miles. I think the major stress on them occurs when going from OD to direct with the throttle closed. Especially when in third, which I did very often. Just makes sense with a 1600 cc engine.

When Tiger Tom was giving the flashlight tech session in Georgia, he stated the major cause of failure was twisting of the shaft. I've tried to find out which way the shaft twists, i.e. from engine torque or engine braking. Does anyone know?

Bill

The forward torque of the engine whilst in a clutch dump in first would be somewhat higher than the reverse torque under decel in 3rd or 4th, 2 or 3 to one at least.

In any case, once the shaft is tweaked beyond material yield, its only a matter of time before any metallurgical weak point propagates the shaft.
Could happen while happily cruising with light load.