Abstract: A load carrying vehicle such as a grain cart, or the like, and an adjustable axle assembly therefor for selectively changing the spacing of wheels mounted on the axle. The adjustable axle comprises two non-circular end members, and a connector or intermediate member which adjustably attaches the end members to the vehicle frame. The end members each have a shaft or axle attached at one end thereof for rotatably supporting a wheel. The intermediate member has two elongate portions, one of which is fixed to the vehicle and with each having a transversely diverging mid portion to fit and engage the end portions. The intermediate portions when engaged with the end members have side portions spaced apart so when pulled together they clamp the exterior shape of the end members and secure same in selected extended portion. Fastening members secure the two connector members together. Stop members extend from each end member, between the intermediate members and interjacent two adjacent fastening members.