Mechanic was not an employee of the TML Pettibone. He was installing the track on a trackhoe after replacing the final drive. The mechanic had a piece of pipe in the rail link fastened to a chain and attached to a FEL. The FEL was pulling the track back in place. The mechanic was guiging the track over the rollers with the end of the pipe which extended past the track and perpendicular to the track. The weight of the track or some other obstruction caused the pipe to yeild and bend. The FEL operator didnot get the signal to stop. The pipe bent. the chain came off the pipe and crushed the mechanics hand.