Ken, Could the clearance volume be too small? In other words, does one or other piston clout the front cover when the suspension is compressed (or even when the piston rod expands when under steam)? Does the loco always stop in the same position? Can you try packing the axle boxes so that the suspension is compressed slightly, and running on air? Look for clues in whether it stops suddenly or starts to drag as the springs are compressed. Regards, JohnP MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.