What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

How to remove the wing bolts

N941WR

N941WR

Legacy Member
I'm posting this over here because most of the -9's are -9A's and I have a taildragger w/o those pesky gear towers getting in the way.

Today I tried and failed to remove my wings. The reason was the lower right AN4 bolt on the right side did not want to come out.

This bolt is inserted from the aft of the spar and points forward.

We have tried to drive it out with a rivet gun, pull it out with a 3' crowbar, hammer it with a drift pin, etc. All while wiggling the wing and turning the now stripped bolt head. :eek:

If any of you have any suggestions for removing that offending bolt, I would like to hear it.
 
cool/freeze locally

I am not an expert but what if somehow to cool or freeze the bolt. Freezing locally using something like liquid nitrogen:eek: while exercising mechanically. Just a thought out of the box.
 
Can you put in drift pins for the other bolts and then wiggle the wing around? With this bolt being the last one in, I think you might be seeing some binding between the center section and the spar.
 
Slide Hammer

A friend used his good bolts to temp install the wings on a 9A. He needed a way to get them back out. If you can get the bolt out 1/4" or so this might work. He built a slide hammer out of black iron pipe. He cut a slot in about a 1 1/4"-1 1/2" cap the width of the bolt diameter, screwed it onto as long of a section of pipe as would fit into the fuse before hitting something. He slid a nipple about 6"-8" long of a larger size (maybe 2") onto it. He then put another cap on the other end of the small pipe. Slammed 6"-8" nipple against the last installed cap until he got the bolts out. Hope you get the idea.

Be careful using a drift punch. You will flare the end of the bolts.

Alan Jackson
 
Try this

Hi Bill,

Had a similar problem when I had my "event" in January. So, try this. Put the other bolts back in and remove this one first. Sounds overly simple, but once everything is lined up, the stress should be removed from the problem child.
 
Air Wrench

On my 7A, used an air wrench to rotate the bolt counterclockwise while applying pressure from the other side. I took the hardest to reach out first.

Once the bolt was 1/4" out, I was able to put a wrench under the head and use that to apply pressure while spinning the bolt. Most came out easily. Some were a long tedious process.

YMMV.
 
also had troubles removing the temp bolts.

worked well with an air ratchet, and by "pulling" with the socket at an angle to the bolt head while driving it out counterclockwise.

rgds,
bernie
 
I built a special tool

for my 7A when I needed to get one of the close tol. bolts back out. Seems the gear leg weldment needed a little filing for bolt clearance. Anyway, I modified a tool built by Roger Hansen (Dragonmaster fame). It is basically the same "hook" used with a slide hammer that grips the head of a bolt that has been backed out 3/16" or so . The difference is that a nut on the backside of the puller is turned to draw the bolt out. Worked great after air wrench, rivet gun, pry bar, many nasty words all failed.

Wondering, would there be a market for such a tool? I could make them with heads for the different size bolts used in the various Van's models... Haven't worked out the cost, but would probably be in the $50 range to cover material and minimum wage for my time.
 
Have you tried squirting some lube in the bolt holes. Just another thought. The wing is so long that the leverage on the bolts is amazing when they are not properly lined up. You may have indented the side of the bolt and created an edge that is holding it. Good luck! Let us know what works.
 
The combination of ideas will work

These two ideas are the winning combination.

Darwin said: Had a similar problem when I had my "event" in January. So, try this. Put the other bolts back in and remove this one first.

Joe said: On my 7A, used an air wrench to rotate the bolt counterclockwise while applying pressure from the other side. I took the hardest to reach out first.

When I had ?my event? in San Diego 110 hours ago, I went to Home Depot and bought and air wrench and my buddy brought his compressor to the field because I knew there was no easier other way to get these bolts out. Eventually, I was able to work a modified crow bar under the bolt head while using the air wrench to back it out.

You don?t have to (and shouldn?t) beat them out. The up/down position of the wing places an enormous load on the bolts so select the most inaccessible bolts first. By lifting and lowering the wing of my 9, the bolts came out relatively easily.
 
N316RV said:
... He built a slide hammer out of black iron pipe...
Click to expand...
No room, this bolt is on the lower right and inserted from the aft. To get a slide hammer in there I would have to drill out all the rivets holding the floor in place.

LifeofReiley said:
Maybe temp bolts back in and a 4X gun... :eek:
Click to expand...
Tried a 3x gun but there is no room to get it on the bolt straight as the fuselage tapers just forward of the spar.

I had the temp. pins in place but may have to go and drive the BIG bolts back in and give it another try.

The C-clamp idea would work but the end of the bolt is flush with the spar and as I mentioned, the bolt head is stripped. (Who put that 12 point socket in my tool bag anyway? I thought I had tossed all those in the trash!)

Any other suggestions? Keep 'em coming guys.
 
frazitl said:
for my 7A when I needed to get one of the close tol. bolts back out. Seems the gear leg weldment needed a little filing for bolt clearance. Anyway, I modified a tool built by Roger Hansen (Dragonmaster fame). It is basically the same "hook" used with a slide hammer that grips the head of a bolt that has been backed out 3/16" or so . The difference is that a nut on the backside of the puller is turned to draw the bolt out. Worked great after air wrench, rivet gun, pry bar, many nasty words all failed.

Wondering, would there be a market for such a tool? I could make them with heads for the different size bolts used in the various Van's models... Haven't worked out the cost, but would probably be in the $50 range to cover material and minimum wage for my time.
Click to expand...

A photo of what you are talking about would be worth a 1000 words.
 
A few possibilities, Bill. If the C-clamp will fit, but the bolt is flush, consider welding a short section of drift punch on the face of the clamp. Pressure is a better mover than hammering. You can find the sweet spot with the least resistance by watching as you move the wing. Also, the bolt must have moved some distance it the threaded end is flush. You can weld a larger nut onto the buggered head so you can again turn it. It only takes minor precautions to keep from heating the surrounding "stuff." Very scary, but it might be possible to cut off the head and push/drive the bolt out the other way. Without the head, you could tighten the nut and pull the bolt through, adding washers as you go. Would only do that as a LAST resort! Not good ideas, but I'm short on them...

Bob Kelly
 
is by chance the threaded portion mushroomed at all? it would only take a miniscule amount to create more interference. if so push it back in and remove that with a die grinder, then use some of the aforementioned methods. It is highly likey you will have to turn them to get them out. ( which if the head is stripped than i suppose you have been turning anyway) At least you dont have l/g weldments in your way.
 
Last edited:
videobobk said:
cut off the head and push/drive the bolt out the other way.....Bob Kelly
Click to expand...
Bob suggests this technique as a last resort and I have done just that on many occasions. With the right drill motor and sharp drill bits, (carbide is best) it is not that difficult to accomplish. Similar to drilling out a rivet but requiring more finesse, start by finding and drilling the center of the bolt head with a #30 drill bit and generate a pilot hole. That bolt is hard steel but will yield to sharp drill bits, firm pressure, low RPM's and boelube. You might go through 2 or more brand new drill bits to get that pilot hole finally drilled. Extreme care must be taken. Be patient, drill straight and avoid placing any side load on the drill motor. The last thing you want to do is snap off a drill bit into the bolt head.

Once the pilot hole is drilled, bring that hole up in stages...say #21, then 3/16"...then 15/64"...then 1/4". This will be a much easier task. Finally, using a pin punch sized to the hole, snap the head of the bolt off, then drive the remains of the bolt through the hole. If possible, this type punch fitted to a 4X rivet gun works very well.

2r79h55.jpg


Let's say you screw up. The bolt head is now hopelessly mangled and you have no chance of drilling into it any further with damaging the surrounding structure.

There is a Plan B.

This may take a bit more time. Using multiple 2" 60 grit sanding disks fitted to a right angle die grinder, simply shave the remaining bolt head off. Avoid overheating the local area and do wear a dust mask. When the bolt head has been nearly sanded away, drive the remains of the bolt through the hole as described above.

I am not suggesting you do anything that is not done in aircraft production environments somewhere every single day of the week.

Have fun. Its all good.
 
A BIG word of caution about welding to the bolt

Contact pressures (on the inner hole surfaces) between the bolts and wing spar / carry through structure are very very high. Probably up close to material allowables, in terms of stress. I don't know about the 9, but that is the case with the 7 and the 8 wing spars.

Therefore, I want to emphasize the danger involved in welding anything to the bolt that might get it fairly hot. Even a few hundred degrees can anneal aluminum. It might look OK afterward, but then might not take the stress / pressure of keeping the wing in place under elevated loading conditions.
 
Wing Bolt removal

I too drove my bolts in with my rivet gun. On one I put it too far in to get the nut on the threads and needed to pull it out slightly. What I did was go to Harbor Freight and bought a three ft bar with a claw on one end. I filed the claw to fit around the bolt head and under it as it was not flush with the spar. Then when it fit perfectly, I got a three ft cheater bar and with the leverage from this assembly, moved the bolt out. I would favor this method before drilling out the bolts. With the cheater bar, I was able to apply quite a bit of force at the bolt head.

Steve Anderson
RV 7A Flying
Lafayette, La.
 
Rick and Vlad,

There is no access to even try drilling in the center of the bolt. You just can't work accurately down in the hole where the spar bolts. go. We have talked about cutting the head off and pushing it out from the aft side but that might be a problem as well. The reason the bolt went in from the aft side in the first place is the fuselage tappers inward forward of the spar and you couldn't get the bolt in. Of course we could push it 1/2 way out, cut it off, and finish pushing it out.

No one is talking about welding anything to that bolt, unless I missed a post. That would be a great way to trash the entire center section.

Keep thinking, there has to be a way to get this thing out!
 
Bill,
The big advantage you have is that you don't have the A model gear towers. Here is something a bit different that might be worth considering.
Insert two longish hardware store type bolts into the big holes from the rear. Get a sturdy rectangular bar of steel (say 1 to 1 1/2" wide and about 1/2" thick) and long enough to span the length between the inboard big bolt hole and the outboard problem bolt. Drill two holes in the bar to match the spacing of the inserted hardware bolts. I suggest these holes be drilled slightly larger than the diameter of the bolts to allow the bar to "float" on these bolts. Install large area washers over the threaded end of the inboard bolt then install the bar. The idea is to install the correct number of washers such that the bar will be parallel to the spar with the bar resting on the washers at one end and up against the problem bolt at the other end. Install a nut finger tight on to the inboard bolt. Now install the nut on the other bolt and carefully and slowly tighten this nut. This should push a considerable force square to the axis on the problem bolt. If it moves you would need to remove washers to keep the force square to the bolt.
A variation would be to first install a nut on to the problem bolt, install the bar onto the big bolts with both nuts and with the bar firmly against the end of the problem bolt, undo the nut on the problem bolt up against the fixed bar.
If the bolt end is mushroomed or bent then you might be able to cut it off flush with the spar. Use the bar method as described above but drill and tap a hole in the bar directly in line with the problem bolt. Screw a slightly pointed bolt into the threaded hole in the bar so it pushes up against the end of the problem bolt and will hopefully force the problem bolt out as you screw down.

Good Luck,

Fin
9A
Edit. Bill I just re-read one of your posts where you said the bolt was flush with the spar. In this case the last suggestion might be appropriate.
 
Last edited:
Success!

Here is the trick to removing the wing bolts from an RV-7 or RV-9 (Tail draggers only).

First off, I hope none of you ever have to go through this!

The solution is all about the sequence of bolt removal.

Here are the steps:
1. Disconnect the battery & disable the ignition. (You will be bumping switches during the removal process and a hot mag/starter could get ugly.)
2. Drain the wing tanks.
3. Remove the interior panels, wing root panels, etc.
4. Mark and disconnect the aileron push tubes at the control sticks.
5. Disconnect the aileron push tubes at the aileron bell crank and pull the push tube into the wing.
6. Remove wing tips, if possible. (This is not required but makes handling the wings easier.)
7. Mark and remove/disconnect all wires, pitot lines, etc.
8. Remove the nuts from all eight wing spar bolts.
9. Remove the two bolts from the mid web.
10. Remove the castle nut holding the aft spar.
11. Using a 3x or larger rivet gun with a flush rivet set, push smaller AN4 bolts out.

12. Here is where I had problems. The taildragger -7 & -9’s use a small triangular part to tie the side of the fuselage to the spar. These are held in by five or six AN3 bolts that go through the side of the fuselage and the four bottom spar bolts, two large and two small. Using the rivet gun, push all four bottom bolts flush with the triangular piece. (I don’t have my manual so I can’t tell you the part number but the gear leg towers provide this function on the "deluxe" gear models.) Unbolt the triangular piece and remove it. Using the rivet gun, push the AN4 bolts back until they are flush with the spar. Then put the triangular piece back in place and push the two big bolts back in place so the protruding threads hold that thing in place. Holding a drift pin of some type (hardware store 1/4" bolts with the threads ground off will work) with a pair of pliers, put the end of the drift pin the 1/4" hole of the bracket and drive out the AN4 bolts with the rivet gun.

13. Once all the AN4 bolts are removed, using your large “pins”, drive the big bolts out. Just don’t forget to oil them.
14. Two pins, top and bottom is all it takes to hold the wing.
15. Remove the bolts on the other wing before removing the wing.
16. Clean up your work area so no one will trip over tools, air hoses, etc.
17. With the wing pinned in place, get three helpers; one on the wing tip, one on the leading edge, and one on the trailing edge, you in the plane.
18. Remove the aft spar bolt.
19. Drive out the remaining two pins.
20. Set the wing in the cradle.
21. Remove the other wing.

The airplane will not roll over with only one wing on but I wouldn’t want to be pounding on those wing bolts with it out of balance.

One tip, two rolls of fiberglass insulation, stacked on top of one another, work great for supporting the wing. Once the wings are removed, that insulation can be used to wrap and protect them for transit.

Now to load it up and bring 'er home. That should happen this weekend, if not sooner.

Thanks everyone for the tips!
 
Congrats on completing that little adventure. Note to others, don't plan on using that flat rivet set again for riveting without a whole lot of polishing of its face.
 
You must log in or register to reply here.
Back
Top