robertahegy

robertahegy

Moderator/Tech Counselor
I just completed the installation of my new nose gear leg and fork. Van's did a perfect job match drilling the hole for the leg mounting bolt. The machining of the leg was also perfect as the leg fit snuggly into the bore of the mount. I decided to replace the leg along with the fork. I have an aversion to using old parts. It was slightly under sized for the close tolerance bolt, but that was good as I just reamed the hole along with the mount for a perfect fit with a new CT bolt and lock nut with 2 washers.

Along with the fork, I replaced the wheel pant brackets with the new style. They really work nice and make pulling the wheel pant off really easy. I was able to plug the two holes for the axle access, so now I only need the two holes by the wheel pant bracket for removal and inserting the tow bar. I riveted the brackets in and set them in fiberglass, rather than use the screws and nutplates. This is really clean looking and requires only the removal of the two allen bolts to remove the rear half. And I don't need to loosen the axle bolt or jack up the plane to reset the axle torque, as the brackets just slide off the spacer washers on the axle bolt. The pant just slides right off the back with no hassle at all. Love it.

I staked the mushrooms using set screws bottomed out in the mushrooms. They engage in a hole drilled in the fork, but are allowed to float so they do not interfere with proper axle torque. I read Van's notice on the necessity of torquing the axles and I will adhere to that advice. I still think it is a good idea to prevent those mushrooms from turning, though. That is why I decided to use the stakes again.

All that is left now is to finish painting the wheel pant. That was probably the most time consuming because of the removal of the old brackets and installing the new ones. I needed to sand off the paint so I could see the new brackets through the fiberglass so I could drill and clecoe them for subsequent riveting. It was easier the first time because I didn't have to deal with the paint and I could see the brackets much better. I could have reused the wheel pant the way it was, but the new brackets are worth the trouble.

I would estimate the time to R & R the leg and fork at about 3-4 hrs. That would include jacking up the plane, removing the cowl, stripping the leg fairing and wheel pant, removing the fork, removing the leg, reaming the hole for the mounting bolt, installing the leg, swapping out the parts on the forks, installing the new fork assembly, put the leg fairing and pant back on, lower the plane and put the cowl back on. I also set the breakout force, redrilled the cotter pin hole, and cleaned and repacked the wheel bearings. Changing out the wheelpant brackets will add some time, but if you already have the new style or are going to use the old ones, it will go pretty fast.

I replaced the spring washers as well as the large washer under the nut. I purchased extra bolts, washers, cotter pins and nuts associated with the project. A new axle bolt was also installed.

Was it worth it? I think so. The new fork adds some extra clearance and the new wheel pant brackets are sure nice. I fly in the winter with the wheel pants off to prevent snow from accumulating in them while flying off our grass strip. I never had a problem before, but I'm sure this mod won't hurt.

Hope this helps anyone contemplating changing their nose fork.

Roberta
 
nosegear assembly

Roberta,

Your post is helping me solve a mystery. My parts inventory include three large washers, axle size. One is flat and the other two are concave. The plans for my 8A show that one of the concave ones labelled as a U-611 disk spring goes on the nosewheel assembly just above the nut. The other two pieces are not shown on the plans. I found that strange.

In your post you mention replacing the spring washers and the flat washer. Can you (or someone else) tell me where the other spring washer and the flat washer goes, and whether the outside edge of the spring washer should be up or down in relation to the center of the washer.

Thanks
 
tonyjohnson said:
Roberta,

Your post is helping me solve a mystery. My parts inventory include three large washers, axle size. One is flat and the other two are concave. The plans for my 8A show that one of the concave ones labelled as a U-611 disk spring goes on the nosewheel assembly just above the nut. The other two pieces are not shown on the plans. I found that strange.

In your post you mention replacing the spring washers and the flat washer. Can you (or someone else) tell me where the other spring washer and the flat washer goes, and whether the outside edge of the spring washer should be up or down in relation to the center of the washer.

Thanks
Click to expand...

On Van's website under the SB notice for the nosegear, they have drawings. The 2 611's face each other to compress, and the washer goes underneath.

L.Adamson
 
On the 7A plans, they show no washer at the top of the fork (just butt up against the turn lock) and then the two spring washers (top one curves down, like an umbrella while the other curves up and the ODs touch), then the 1 1/4" flat washer, then the nut on the bottom.

Hope this helps,

Roberta
 
Thanks

Thanks to both of you for your responses. They did indeed help. I had assembled the nosegear with only one spring washer installed. I just went out to my garage and corrected that mistake based upon your information.

I hate having parts left over after I have build something.
 
A friendly tip on those spring washers... The edges of those washers, where they touch each other or the nut (or bronze bushing as is the case on the upper one), are fairly sharp. Two problems there. One, they will grind down and the breakaway force will drop, needing adjustment. The other problem could be that they may carve on the bronze bushing. I took both sides of both washers and sanded a little bearing surface on them. Just a little flat, maybe .020" wide. I laid a piece of 400 grit emery cloth on a surface and just worked them a little bit. I've never had to adjust the breakaway force after the initial setting.
 
Nose Gear the hard way...

I also completed my nose gear re-work this long weekend, though I went about it the old fashioned way re-using all my parts. Here's how it went...

The stock fork came off, stripped it of bolts and bushings, and I hacksawed off 1" from the bottom. This took about 1 hour of sawing by hand. I *highly* recommend a powered saw by all means. A die grinder then sliced the bottom wedges (moving aft) toward the axle. The rough cut is now done.

Then came a bunch of grinding & filing & polishing to get everything parallel and airworthy. I stopped when the top and bottom bushing faces were within 0.005". The major fork work is now done.

With the weld on the bottom removed, I needed to get some strength back. I was not interested in re-welding and heat-treating the fork, so I chose to add a 5/16" dia. x 5/8" long allen head "set screw" as a shear pin. This is placed just aft of the fork pivot, and 3/8" above the cut, in the meaty hunk of aluminum fork. Drill & tap, then set with locktite.

I also added a couple 3/4" lightening holes near the axle, just like the new fork. This was followed by a deburr and cleanup, with a shot of paint to finish. Pound the bushings back in, replace the bolts and grease zerk, and it is ready to install. Note: the stock zerk location *just* clears the bushing when re-installed, so it did not require any modification.

Now the really hard part...threading the gear leg. We did it on the plane. I used an adjustable die with 18" extension handles on both sides of the die holder. It took 2 guys wrestling the die for about an hour to cut the threads. The gear leg gets so hot you can almost burn yourself! Used lots of oil and backed off 1/8 turn after every 1/2 turn cutting. It took 3 passes while necking the die down to get the nut to easily spin on. (The next day I was a sore puppy!) This die was able to get 2 gear legs cut and is now missing many teeth...pretty much trashed.

Last step is to die grind off the bottom 1" of the gear leg, clean up with a grinder, redrill the cotter pin holes, and put it all back in place. Same mounting for the wheel pants...so no changes there. Went for a test hop and my first comment is...no more nose wheel shimmy at ~18 knots...that's nice! Hope it stays that way.

Split the cost of the die so my total investment was about $30 and maybe 8 hours of work (some of which is very hard). If I did it again...I would send the leg to the shop for cutting of the threads. The $100 saved was a pain of hard labor and I'm not 21 any more like my helper. Doing it in a vise would be a little better, but not much! The other work was just another day of building airplanes, which is much like fishing, only more productive and always satisfying.

Happy New Year and Blue Skies!
 
The Gear Leg From ****!

A Personal Nose Gear Experience:

To underline what Kelly said: If you elect to rethread your existing nose gear manually, that manual work is definitely the hardest part of the entire process. For my gear leg, it took three dies, several friends (we had to turn the die handle in shifts) and four hours! The same basic crew had previously rethreaded ten RV gear legs, and those legs only took about an hour apiece to rethread! . . . But Not Mine! . . . "The Gear Leg From ****!" My gear leg appeared to be much harder/tougher than normal.

In the end, my gear leg turned out fine (the new threads are beautiful, in fact!), but I'm still taking ibuprofen for the aches and pains from turning that die handle. Unfortunately, I assume my friends are also in similar shape; for which I sincerely apologize! They'll probably hit me up for a free lunch at the Cable Airport Air Show tomorrow, and I'll only be too happy to buy them one!

I talked with Harmon Lange today, and he said that all the gear legs go through the same heat treat/quench process, and, therefore, they've never noticed much variation in physical properties, including hardness. Harmon surmised that possibly the first die we employed was previously used, rather than brand new, and in the process of cutting the first new threads, we may have inadvertently deposited some of the die material itself on the gear leg. As a result, from that point forward, we may have been cutting some hard die material as well as the gear leg itself. At this point, however, we're still not sure WHY my particular gear leg was so difficult to cut . . . I'm sending the 1-inch cut-off section to Harmon so that he can test it.

Well, anyway, some possible lessons learned for your consideration:

1. If you're going to rethread your gear leg manually, make sure that you're using a brand new die for your first pass.
2. If you run into trouble threading, it might be best to stop the manual process. In other words, if the threading starts tough, it apparently stays tough! Some options at that point:
(a) Send your gear leg to Langair or a similar machine shop with automated machining equipment capable of handling the entire gear leg, or
(b) Purchase a new gear leg from Van's, or
(c) Other? (. . . maybe someone else on the forum has some more options/recommendations)

Well, anyway, I thought I would share my gear leg experience in an attempt to help other RVers avoid what I, and my friends, went through with "The Gear Leg From ****!"

Best Regards,

Bill Palmer :eek:
 
match drill

any comments from those who have purchased a new nose gear leg and did the match drilling??
ie
Need special drill bit to withstand the hardness?
Had to build a jig?
etc

Thanks for the input-I have mine scheduled for the teardown/swap end of month.
 
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