Page created 1/31/99 and updated 2/9/99
(Click on images for full-sized photo)
If you're disassembling your Stinson for restoration, you'll want to remove all of the controls so that you can sandblast the fuselage. One of the puzzles I encountered was how to remove the torque tubes for the rudder pedals. I've seen that others have had the same problem. Once you understand how they are put together, it's not so hard. For a diagram of how the pieces fit together, see page 46 of the Stinson Voyager and Flying Station Wagon parts catalog.
This photo is taken from the passenger's side of the fuselage.
Each of the torque tubes rides on a bearing at each end. The bearing slides into a machined area at each end of the tube. The bearings are attached with an AN4 bolt, washer and a locknut to a bracket welded to the lower longerons on the outboard ends, and to angle brackets bolted to the fuselage framework on the inboard ends. Removing the bolts that run through the bearing at each end of the torque tubes is only possible AFTER pulling the bearings out of the tubes. This is because the head of the bolt in buried inside the torque tube.
This photo is taken from
the pilot's side. You can clearly see the
You should be careful in removing these bearings so that they can be reused. Bearings of the same size are not readily available. (If you do damage a bearing, there is a solution, so don't panic. More on this later.)
In theory, you should be able to remove the two small bolts and nuts that hold the L-shaped inboard bearing brackets to the fuselage, then slide the tubes off of the outboard bearings, sliding the tubes inboard about an inch. If you're able to do this, good for you. I found the bearings were frozen to the tubes and I could not easily slide the tubes off of the outside bearings. Try soaking the ends of the tubes and bearings with penetrating oil to make them easier to remove. Some gentle tapping (use a plastic mallet or protect the components by using wood blocks) may result in success.
If this fails, you can use a Dremel tool or something similar to cut a slot in the outboard (threaded) end of the bolt that holds the bearing and outboard end of the torque tube to the welded bracket on the longeron. Then, using a small screwdriver to keep the bolt from turning, use a wrench to remove the nut. You can then remove the torque tube from the fuselage. In this case, the bearing is still in the tube and you will need to remove it. Assuming you are able to remove the bearing on the inboard end of the torque tube, you could use a long piece of tubing, just a bit smaller in diameter than the torque tube, to tap the bearing out from the opposite end.
If you are unable to slide the bearing out of the inboard end, you'll need to use force to do the job. Clamp the inboard bracket in a vise and yank on the tube to pull the bearing out. With this crude method, chances are you will damage the bearing and will have to replace it. Once the bearing on one end is out, use the piece of tubing mentioned above to remove the bearing on the other end.
I damaged one bearing during my efforts to remove it from the torque tube. I was unable to find an exact replacement bearing. The part number for the original bearing is a CS-1280. The bearing I used as a replacement was a Fafner KP5A from Aircraft Spruce. This bearing has the correct outside diameter of .8125", but is sized for an AN5 bolt instead of the AN4. I used a small bushing so I could use the original AN4 bolt.
If you or your mechanic are making this change, your AI may require a 337 form and field approval.