landing gear bolt holes

[33alfa]

Ok guys i recently purchased steel axels for my A model, also adding ski fittings and this is the reason. Or so im told. Anyway the the bolt holes are larger from top to bottom on new units. Do i have holes drilled or whats the the correct thing to do? Thanks for all the help in the past as well. Also putting steps and handles for the windshield cleaning. Any install info? . By the way George, the new tail bracket looks great . If i break this one ill be impressed.

[GAHorn]

The older landing gear used AN5 bolts for both upper and lower. The later gears and axles used AN6 for the lower (to increase strength.) Additionally, NAS bolts were approved as alternates (also a strengthening increase). The NAS bolts are probably overkill for wheeled aircraft, but are adviseable for ski-equipped airplanes.

You may drill out your lower landing-gearleg axle mount holes to accomodate the 3/8" dia. AN6 bolts. Be certain to get rid of the stress-riser caused by the sharp edge of that new hole by light-radiusing the edge of the new holes. (NAS bolts require radiused holes in any event.)

[33alfa]

Thanks George. Just to be clear It is the lower holes correct. I was worried that id be taking to much meat away from the bottom. And i did go with tha NAS bolts but it hurt! Roger

[GAHorn]

The upper bolts are NAS145-41 and the lower bolts are NAS146-42 (unless you also installed the tow-adaptors, in which case you'll want to go one step longer.)

If you went to the trouble and expense of NAS bolts, be certain to also install NAS nuts. (NAS365-524C and -624C). No reason to have a 10,000 lb-test chain and use 2,000 lb test hooks on the ends.

(I've moved this discussion from the MX Library to the Hangar.)

[N171TD]

Bushings are another remedy. These bushings are a cessna part but may be difficult to aquire.

[c170b53]

When I put new Cleveland brakes on my plane, the kit came with bushings. Cleveland brakes might be a source.