Tip: RV-8 Self-Locking Gear Nuts

The longer I worked inside the RV-8 gear towers with vent lines, brake lines, all the weldment screws and wiring, the more I thought about laying on the cockpit floor trying to get a socket on those nuts when it came time to mount the gear and do annual condition inspections/maintenance. I have heard a lot of builders comment on the unpleasant task of working in those gear towers. Anyway, I think I have come up with a simple mod to make gear bolt/nut torquing much easier.

I purchased four inexpensive 9/16" stubby wrenches from Lowes at $5 each. I cut the box end portion of the wrench off with just a bit of the handle remaining and ground it to fit down inside the gear weldment where the outboard gear nuts are located. I cut, ground, and fitted each of the four "mini-wrenches" to fit the four bolts. Using JB Weld, I then epoxied the landing gear nuts into the wrenches and let them cure. Since the four special fasteners were custom fitted I marked them so I wouldn't mix them up during installation. Since pictures are much better than words I have attached a couple photos that should be helpful.

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I like it! Good tip Pete!
I just got through wrestling these during my annual and even with removable webs on my towers it was still a major pain.

Thanks for sharing!

Thanks for the feedback, Brent. I modified my gear towers as well to get a little more room to work but even so, it is a real pain anytime I need to do something inside the towers. Another nice benefit of this mod is that I should be able to check and torque the gear bolts/nuts without a helper.

I am going with some 12 point nuts that have higher tension than the nuts supplied by Vans after reading of some failures on here. If you are interested, I am currently installing a set of bolts and nuts with special washers that Tom Brink of GAHco got together for me. I have not installed them yet but should have them in a few more days and will report back the results. If interested you can contact me or Tom Brink and fill you in on the details.

bird

I'm interested in seeing how these work out. Keep us posted please!

real innovation

Hi Harley,

This seems to be a really great idea. I used the same kinds of nuts but adding the box wrenches on is brilliant. I'm having trouble seeing any kind of a downside to this idea, except the very small amount of extra weight. I think I will be buying some wrenches.

Mickey

I opted to go with the nuts that Van supplies in the kit for securing the landing gear. I have read, however, that some builders are going to the twelve point nuts for added strength. I would assume that the same approach would work for the twelve point nuts as long as you can find an appropriate box end wrench to modify. I wouldn't be surprised if a twelve point wrench costs a bit more. Still, if it results in added strength and peace of mind it is probably worth the expense.

Once I install the gear legs I will post a report.

Harley O. (Pete) Britton said:

I opted to go with the nuts that Van supplies in the kit for securing the landing gear. I have read, however, that some builders are going to the twelve point nuts for added strength. I would assume that the same approach would work for the twelve point nuts as long as you can find an appropriate box end wrench to modify. I wouldn't be surprised if a twelve point wrench costs a bit more. Still, if it results in added strength and peace of mind it is probably worth the expense.

Once I install the gear legs I will post a report.

Click to expand...

Harley,
I doubt the 12-point wrenches cost more...you found them at Lowe's for $5 each... (the wrench heads in your photos are 12-point)

200 ksi Tensile Nuts. & more hardware!

When user name bird lets me know how the custom selected hardware fits, then I will release the proposal to others who are interested.

Well DUH.... I never even thought about the twelve point nuts fitting the std 9/16" SAE box end. My immediate thought was the twelve point nuts would require a different and special wrench. This could be a first. A fastener that doesn't require another specialty tool.

Must have went brain dead for a few minutes.

Thanks,

Pete
RV-8 Fuselage/Finishing Kit, Archer for Flying

as I recall the 12 point nuts were 1/2 inch, giving even more clearance. Have stripped, lost, found loose, 3 of the stock nuts, I found the 1/2" 12 point replacements easy to deal with with a 1/2 inch socket u joint on an extension in the towers.
In other words, if you use the stronger nuts, you can get a socket in there with clearance around the other nuts in the area, nullifying the need for the cut wrenches and epoxy.
NOTE. get those little nuts and bolts surrounding the gear bolts turned around during the build process. Getting the bolt heads inside the tower should be done regardless of the nuts used.

Hopefully I will be able to get the 12pt. Bolts and nuts installe this week and give an update. I just read Kahuna's comment on putting the bolts in the gear box also. I have been considering this also, I don't know if the nuts will protrude out past the cover plate or not. but that might not be a bad idea anyhow as they could easily be inspected. I am still thinking about this and me thinking, hmm now thats dangerous lol!

Bird

Taking action is powerful

Great solution Pete, I imagined your idea exactly, but cussed and bitched the whole time I was fighting to do there nuts the stock way.

I'd buy a set now just to have in my tool box when my first inspection comes around.

I have installed the hardware that Tom Brink with Gahco sent me onto my rv8. I have them torqued and they fit very well. The special washer under the bolt head and one washer under the nut, worked perfect. They torqued down good and fit is perfect. So, it was successful. The outboard bolt heads will not be covered under the cover plate. It is not an issue for me, I am not positive but I think the intersection fairing will cover it. I just have to provide some relief holes in the cover plate for the heads being they are taller than the standard bolt. I gave a lot of thought to putting the heads inside the fuselage gear box facing down, like some have done, but decided to put them like the plans said. The nuts in the gear box where very easy to get a socket with a universal on, then about 13inches of extension and it was out of the box and easy to put a ratchet on. The bolts and nuts are 12 point. Very good, no pains.

The nuts Van's provided may be strong enough, but marginal in my opinion After studying the washers that Vans sent me, I think I found the real problem that others have had. The washers are hardened but not aircraft standard, therefore the outside diameter is larger. Now this washer will interfere with the "u" channel radius that they must fit in. If these washers are not ground down to provide a relief, the nut will have stress on it that it was not designed for, causing failure.

I am satisfied that the hardware will be of good service, so that's one area that I will not have to be concerned about anymore. If anyone else is interested in getting this hardware just contact Tom Brink and Gahco, he is an advertiser here on VAF. He also has some pics that I sent him of the install that I am sure he would be happy so send anyone interested.

Airplane actually rolled out of the shop for the first time!! Yay!!

bird

Reversing gear bolts?

Have just received my QB -8 fuselage and am about to drill gear attach hardware.
I immediately wondered why the plans call for the bolts to be installed upside down , but suspected it was to insure that the cover plate fits over the bolt heads...
Could it also be that you can not remove the bolts from inside the towers after all the plumbing is in there?

I'll take a set

Seriously, how much?

The bolts went in fine on my QB (gear towers complete) so I hope they'll come out just as well! There's a lot more stuff in the towers than was there was when they were installed....