checking clearance--Pull the concave up to the zero setting and check clearance on the 3rd crossbar from the front, and the 3rd crossbar from the rear (assuming it has been replaced with a 13 crossbar Titan II concave since that was what was likely available 1000 acres ago--original had 14 crossbars) clearance between the tallest cylinder bar and the concave crossbar should be 1_8"-- thereabouts in the rear, and 1_4" in the front. This gives you a wedging action as material travels thru and a gradual squeeze. As you open the front of the concave up to let material in, this ratio will be somewhat maintained. This should allow somewhat slower cylinder speed, and should help prevent chewing up the trash so badly while keeping grain off the walkers. Another question--do you have filler plates installed on your cylinderIJ If you do, they will contribute to your problem since they hide the front of the cylinder bars and will present problems with feeding trash thru without high cylinder speed. Hope this is reasonably clear--email if you'd like, and we'll try to help.