Alternative to reaming nose gear bolt?

[andrew phillips]

I have been reading the threads regarding the replacement of the nose gear bolt with close tolerance bolts or taper pins. I don't think I actually came across a single report of someone doing this successfully with the engine and mount still on the plane. Just throwing this idea out there. What about a new hole drilled through at 90 degrees to the existing one and several inches lower down the leg? I'm looking for a way to remedy this problem without removal of motor mount.

[frankh]

You'll find that gear leg is as hard as nails..Personally I would risk it.

Frank

[ClayR_9A]

I haven't figured out why Vans doesn't drill that hole horizontally in the first place. (yes, it would have to be a couple of inches down instead of at the end of the leg, though) Can anyone explain that?

[Martin Sutter]

The gear leg has two bearing points inside the socket; a cylindrical one on top and a spherical one where it exits the socket on the bottom. The area in between has a smaller diameter and does not make contact with the socket. This arrangement permits the leg to flex with out placing a high stress point where it exits the socket. Since the top cylindrical bearing area is only about 1 1/2" long, moving the bolt down 2" would not be possible.

Martin Sutter
building and flying RV's since 1988

[Finley Atherton]

Originally Posted by andrew phillips

I have been reading the threads regarding the replacement of the nose gear bolt with close tolerance bolts or taper pins. I don't think I actually came across a single report of someone doing this successfully with the engine and mount still on the plane.

I recently did mine successfully with the engine and mount on the plane. I went 1/64" oversize and turned the piloted reamer by hand rather than with an angle drill. I would guess that it would be OK to use the reamer in an angle drill if you go slowly and carefully especially when reaming the socket.
Firstly I pushed the bolt partly out the bottom and then reamed out the top hole in the socket (the hole in the strut acts as a guide for the piloted reamer) Next I removed the bolt and strut and reamed out the hole in the strut on the work bench. Lastly I reinstalled the strut and carefully inserted the reamer through the top hole and strut and reamed out the bottom hole of the socket.
There is not enough room above the mount socket to use a tap holder so I turned the reamer in the mount socket with a small ratchet socket driver being careful not to apply a side force to the reamer. Use some type of cutting compound. If I was doing it again I may consider dulling the part of the reamer adjacent to the already reamed upper hole before cutting the last, lower hole in the mount socket to avoid the possibility of accidently enlarging the upper socket hole while reaming the lower hole.
The final fit, especially in the strut, was very tight. I actually had to lightly sand some of the clad plating off the close tolerance bolt to get it in!
Reamer was from gen-aircraft-hardware.com
YMMW.

Fin
9A

[Zero4Zulu]

This is how I intend to fix my loose nose gear. The washers will be 60 degrees made from toolsteel and heat treated a little harder than the bolts. The taper in the nose gear mount can be done with a standard 60 degree countersink. The wear I discovered was only the bolt hole and the bolt where it rides in the mount. The middle portion of the bolt still fit snug in the gear leg. With this method I can retighten the bolt from time to time and have a positive tightening effect.

You can't retighten the taper pins with out re-reaming the hole because the pin will not move deeper into the hole.

This method is used in some cases of old aircraft restoration.

[mayo3808]

Andrew,
I install a one over size bolt in my RV-9A while I was building. Engine was hung and completed. I purchased a adjustable reamer from MSC and bolt from gen-aircraft-hardware.com. I used a angle drill attachment and battery drill then installed the bolt from the top. Very tight fit. Take the weight off the nose wheel before starting. Worked ok for me no problem.
Brent