Help me out folks - how do you get the tunnel off to access the springs?
On a straight-tail? It's been awhile, but as I recall you had to first remove the two square sheet-metal scuff plates (heel plates) just aft of the rudder pedals (four screws each). That then exposes the screws holding the center tunnel to the floor. There are also four(?) screws that hold the aft end of the tunnel to the bulkhead the runs from door-to-door.
Finally, there are four(?) screws that hold the front of the tunnel to the firewall. These last screws are particularly difficult. Sometimes you can't see them because the firewall insulation is torn and covers the screw heads. You also need a long phillips screwdriver to reach past the rudder pedals. And the screws are prone to dropping into the floorboards under the rudder pedals.
Once all the screws are out, you have to flex the tunnel a bit to get it out and around the control column. You'll probably have to remove the "beauty shield" on the front of the control column for clearance.
