Combines case ih 1056 xl

I have a 1255xl and the lower speed is controlled by a lever ontop of the box closest to the hydraulic top on the right before the trailer brake valve and spool valves. There is only drop speed there, if it is slow to lift you may need to drop the oil and change the suction filter under the tractor housed in a round housing with a large pipe comeing off it.

Not sure on hidraulics but the transmission in a 1255 and 1455 were ZF, IH on 1056.

I mean maybe hidraulics work different