assembly 13 is a track binding idler wheel and as will be described later it provides a binding spring force against the inner surface 15 u2032 of an endless track 15 trained over a portion thereof the endless track suspension further comprises a drive sprocket 14 secured at an elevated position above the suspension support beam 11 by support means herein a support arm 16 a plurality of support wheels 17 are secured to the suspension support beam 11 and project from a lower face 18 thereof these support wheels 17 are provided on opposed sides of the support beam 11 as herehinshown there are two support wheels 17 on each side of the support beam as also hereinshown the drive sprocket 14 is provided with sprocket teeth 14 u2032 which are in engagement with sprocket receiving holes 19 provided all along a central longitudinal axis of the endless track 15 each idler wheel assembly 12 and 13 is comprised of a pair of wheels 12 u2032 and 13 u2032 each pair of wheels is supported on an axle 20 and 21 respectively the support arm is also secured to the suspension support beam 11 by a torsion pivot connection 22 the upper end of the support arm is secured to a connecting shaft of a cap secured to the drive sprocket as will be described later and a cover 23 shields this connection.