Neutral position on speedometer on dodge t110

[serge]

Hello

CANADIAN DODGE T110 D60 L5 or CANADIAN DODGE T110 D60 L12 own a two speeds rear axle (the first with single rear wheels and the second with dual rear wheels).

During the restoration of it’s CANADIAN DODGE T110 D60 L5, my friend found a wire which began on the sihft used to engage the low speed on the rear EATON axle and ended to the speedometer.. On the DODGE T110 technical manual , in the chapter « rear axle », a method to adjust this strange system is described but we don’t have understood i’ts aim..
This system means that the speedometer has a neutral poistion !!!!

I suppose that when we drive the truck with the low speed engaged , the speed of the truck is very low and can cause damage to the speedometer due to the jitter of the arrow of the speedometer.
Is any body an explanation or had used this system?
The following pics show the technical manual copy, the system on the shift level and the hole and the wire on the front of the cab.

Regards to every