scsmith
Well Known Member
There have no doubt been other postings about how to solve the problem of play in the bolted joint that holds the tailwheel swivel fitting to the tailwheel spring. I figured I'd show some pictures of how I solved this problem.
With only 100 hrs, the two AN3 bolts that hold the tailwheel swivel fitting on had enough play to be a concern. So I bought a tapered reamer and a couple of AN386-1-9 taper pins. These are 0.205 at the small end, so just slightly bigger than an AN3, and on the other side of the fitting which is 0.875 diameter, the taper pin diameter is just about 0.25.
I inserted the pins from either side to maintain maximum edge clearance between the pins. The grip length of the pins is 1.125, so if you ream until the shank of the taper pin just comes through the fitting, you will have a 1/4" "head" on the pin exposed. I went just a hair deeper than that. The cupped washers were (partially) radiused to seat onto the round side of the swivel fitting.
Now the tail wheel assembly is tight on the spring. IF it ever works loose, I can just tighten the pins a bit more, but I surely doubt it will work loose, there is nice tight-fitting surface contact all the way around the pins.
ASC has the taper pins and cupped washers, and the reamer.
You may also notice that I've replaced the integral rod-end plus post that was supplied with my steering link with a standard rod-end bearing and AN3 bolt. I could not quite fit an AN970 washer on this one, the bearing is almost at the limit of its angular allowance when the tail wheel is off the ground, and an AN970 washer would have interfered with the angular allowance. So there is an AN960 washer there. It provides partial retention if the ball pulls out of the bearing seat, but not if the bearing seat pulls out of the forging.
I suppose I could file a flat spot on one edge of an AN970, or bend one edge upward a little, to get full retention and not interfere with the angular allowance.
With only 100 hrs, the two AN3 bolts that hold the tailwheel swivel fitting on had enough play to be a concern. So I bought a tapered reamer and a couple of AN386-1-9 taper pins. These are 0.205 at the small end, so just slightly bigger than an AN3, and on the other side of the fitting which is 0.875 diameter, the taper pin diameter is just about 0.25.
I inserted the pins from either side to maintain maximum edge clearance between the pins. The grip length of the pins is 1.125, so if you ream until the shank of the taper pin just comes through the fitting, you will have a 1/4" "head" on the pin exposed. I went just a hair deeper than that. The cupped washers were (partially) radiused to seat onto the round side of the swivel fitting.
Now the tail wheel assembly is tight on the spring. IF it ever works loose, I can just tighten the pins a bit more, but I surely doubt it will work loose, there is nice tight-fitting surface contact all the way around the pins.
ASC has the taper pins and cupped washers, and the reamer.
You may also notice that I've replaced the integral rod-end plus post that was supplied with my steering link with a standard rod-end bearing and AN3 bolt. I could not quite fit an AN970 washer on this one, the bearing is almost at the limit of its angular allowance when the tail wheel is off the ground, and an AN970 washer would have interfered with the angular allowance. So there is an AN960 washer there. It provides partial retention if the ball pulls out of the bearing seat, but not if the bearing seat pulls out of the forging.
I suppose I could file a flat spot on one edge of an AN970, or bend one edge upward a little, to get full retention and not interfere with the angular allowance.
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