Hi Jim; I ran into a few issues. Aside from a couple that were purely caused by myself and my son trying to treat the airplane like a tractor, the main problem was that the replacement AN5-20A bolt to secure the nose gear strut to the engine mount was about .001" bigger in diameter than the one being removed, and simply would not fit. I ended up ordering another 6 bolts, measuring them, and trying the smallest of the bunch (they varied by .001 to .002 from the smallest to the largest). Fortunately I was able to tap it through and finish the job. I was not, however, able to insert the bolt from the bottom as per current plans; this would have required cutting a hole in the firewall, which would have been doable except that my battery box is immediately behind the firewall in exactly the same location. The old bolt was pristine after 400 hours, so I was comfortable putting the new one back in head up, just as the old bolt had been. The problem with this orientation is that you can't get a torque wrench on the nut; I therefore tightened it according to what my old air force tech friends call "German torque" (guttentheidt).
Clearance and space to work are the big issues working with this bolt; clearance between the end of the bolt and the firewall, between the nut and the firewall, finding room to get a hammer in to tap the bolt through the holes; all challenging. I also had to tap the bolt "just" through the engine mount in order to be able to get the nut on, and then draw the bolt through the rest of the way by tightening the nut. If the bolt was inserted further, there wouldn't be enough room to get the nut in place. Relatively minor stuff that turns what would otherwise be a 10 minute project into a couple of hours of head scratching and experimenting (and a bit of cursing).
On the positive side, the holes through the engine mount and gear strut were not worn or enlarged at all; everything was still nice and tight even before I changed the hardware, despite my stop flange having been mounted backwards. The flange itself did not fare so well; It was split from the excess force caused by the incorrect orientation. My theory is, however, that the flange "giving" when the wheel hit the stops decreased the shearing force on the strut mounting bolt, and helped to prevent damage up there.
I ended up replacing all the relevant hardware; the mounting bolt, washer and nut, the stop flange itself and its bolt, washer and nut, and the disc spring and washer under the nose gear fork. The hardware is cheap, and you'll pay more for shipping than the parts anyway. My other suggestion is to order multiple bolts (they're under a buck each) for both the stop flange and the gear mount to maximize the chance of having one that fits properly the first time. I learned that one the hard way, and lost a lot of time (not to mention double the shipping costs) getting it right.
Sorry for the lengthy response; you probably weren't expecting to read "War and Peace" but I hope it helps!
