“Tag” Vs “Pusher” Axles – Excel’d

To understand the mechanism we need to understand the type of Axles:

1) Tag Axle – A dead Axle situated behind the Drive Axle.
2) Pusher Axle – A dead axle located immediately in front of a drive axle.

In a 37T vehicle there are two options for fitting the axle. The vehicle can be fitted with “Tag” Axle as in the case of Tata 3723 or “Pusher” Axle (like in Tata 3118).”Tag” or “Pusher” Axles can be Fixed or Lift depending upon the Product Design. Tata is providing “Lift Axle” in 31T & 37T which is outsourced from Hendrickson.
Tata 3723  Rigid Chassis Truck with Tag Axle
Ashok Leyland 3723 Rigid Chassis Truck with Pusher Axle

Tag Axle has few advantages over Pusher Axle:-

1) Tag Lift Axle gives 150mm-180mm ground clearance as there is no propeller shaft to restrict its lift. In Pusher lift Axle, “lift” gets restricted to 120 mm.

2) Turning radius of vehicle is reduced considerably by using a “Tag Axle”. Since both Tag & Pusher axles are self steered, Pusher Axle being in front has more turning angle hence larger turning radius.

3) Having a Tag Axle gives you choice of having multiple wheelbases (Hence choice of different Cargo Deck Length) of the vehicle as it eliminates major redesigning of the vehicle.

4) Weight get evenly distributed when the Tag Axle is lifted as compared to the Pusher Axle which put extra Load on Drive Axles when in Lift Position. Tata 3723 is fitted with anti theft feature by which the “Tag Axle” if in lift position comes down automatically when the engine is turned off. This is to prevent theft of Tyres which can be easily removed when in lift position.Also the moment vehicle is put in reverse gear the lift axle is raised automatically to prevent dragging of Tyre while reversing.



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