Abstract: A track-carrying frame is attached to a vehicle axle, preferably as a temporary replacement for the vehicle wheel, as is disclosed in application Ser. No. 413,443, filed Nov. 7, 1973 now U.S. Pat. No. 3,834,771. The present device comprises a track guide attached to the bottom of the frame which cooperates with lugs on the inner faces of the track to prevent the track from moving laterally off the frame and the sprockets, idlers and bogie wheels mounted thereon. Further, the device restrains the frame from movement relative to the vehicle from its normal horizontal position into an inoperative position when the frame momentarily is out of contact with the ground.