Rotation of the 7A nose gear

[jeff beckley]

Recently I have noticed that the leg of my 7A front gear is rotating slightly where it mounts into the engine mount. There is a single bolt to hold it into place. The mount is starting to elongate around the bolt allowing the gear to rotate. This is causing a small feeling of directional instability during rotational speeds. Any suggestions of how to correct this?

[Jamie]

I've never heard of this happening side to side like you mention. I've heard of it working fore and aft but not rotationally.

I would call Van's on this one to be sure but I would probably step up a bolt size and use a NAS close tolerance bolt. Also I would use a reamer to get a perfect hole as possible. I helped a friend do this without removing the engine or mount.

[Canadian_JOY]

Don't want to cast unnecessary dark shadows on this issue, but do want to add a little "real world" feedback. The Whitman Tailwind uses the same gear as the RV6A (yes, exactly the same, Tailwind builders often order their gear legs, wheel pants etc from Vans). A local Tailwind builder had a nosegear collapse on landing as a result of that single crossbolt shearing, allowing the entire nosegear to rotate in its socket, and, unfortunately, the prop to contact the pavement.

My advice to anybody who's got even a little "wobble" in that nosegear mounting bolt is that it demands immediate attention in order to avoid potential catastrophic failure should that critical bolt fail.

[GrayHawk]

I agree on the fit of the bolt. My engine mount hole has wear due to being drilled out (sloppy) to 3/8" before I got the plane. I had problems with the nose gear when I first got the plane which caused me to completely re-build the nose gear. I now watch it very carefully.

I meant to post this photo on the other thread but here it is. Bolt on the right was the bolt I removed when I first got the plane (you can see the wear/shear point and a bend). I then started carefully fitting close tolerance bolts and checking/changing them every year (center bolt). Bolt on the left is a new spare bolt.

[frazitl]

Take a look at:

http://www.matronics.com/wiki/index....ose_Gear_Strut

I seriously considered doing this on my initial install for my 7A, but used a reamer and a close tolerance bolt for the first go. Looks like a good solution, and might work for alignment issues or looseness issues on the mains too.

Keep the shiny side up.

[Oldgeezer]

Originally Posted by frazitl

Take a look at:

http://www.matronics.com/wiki/index....ose_Gear_Strut

I seriously considered doing this on my initial install for my 7A, but used a reamer and a close tolerance bolt for the first go. Looks like a good solution, and might work for alignment issues or looseness issues on the mains too.

Keep the shiny side up.

I just recently completed installing the tapered pin following Jim Ellis's procedures and now have a very tight fit, but it wasn't easy and required buying a second tapered reamer from Travers Tool. If anyone wants to know the process I had to followed I would be glad to post it.
I initially tried the close tolerance bolt procedure but jumped ahead of myself by buying a straight reamer from Avery that was .3115 and then pre reamed the mount and gear leg before getting the CT bolts which I found were .3112- .3113 in size ( didn't do my research). Even with only .0002 difference, I could still grab the gear leg and rotate it ever so slightly in the mount and new this would cause problems with wallowing the holes later. can't find anyone who sells a .3112 reamer , so as others have recommended, buy an adjustable reamer ( Travers Tool has them) and go slow to get a tight tap in fit. I initally thought that I would just buy an oversized ct bolt and found the price really shot up. Already had the taper pin, so changed my plans.

Oldgeezer
RV9A

[flydjd]

Originally Posted by Oldgeezer

I initally thought that I would just buy an oversized ct bolt and found the price really shot up.

Oldgeezer
RV9A

Hi from Europe, could I please pick your brains re suppliers for the oversized close tolerance bolt, specifically a .3115 CT bolt.

I have had the very same problem with the rear wing spar attach bolts - reamed them out to .3115 using Avery 5/16" undersize reamer stupidly assuming that they were .3125 (5/16") and then finding they are .3110 and loose in the hole !
(There have also been other posts on this point - I feel a warning from Vans on the plans would help with this issue as they say it is not desirable to have movement for this bolt location - glad I didn't use a 5/16" drill.)

GAHco is one supplier but I am having a problem email'ing them as an International customer - also I am not sure that they have a .3115 CT bolt. Also looked at A/c Spruce - no luck.

[frazitl]

GAHco's PPR-.3106 reamer. Designed for a slight interference with a standard close tolerance bolt. Wish I had found these before I reamed my nose gear bolt hole to .3315

link below.

http://www.gen-aircraft-hardware.com...228~228&id=230