Torquing landing gear bolts

I'm working through the first condition inspection on the RV-8 I bought, and need to check the torque on the landing gear bolts. I removed both access covers so I have access to the bolt heads, but how in the world do you get at the nuts in the towers?

...I can't wait to read the responses to this question.
I am wondering the same thing...

I have seen various methods, usually requires a crows foot, with the sides grounded off, and a steel rod welded to it to get it down in there. The best you can hope for is that while one person spins the bolt from underneath slowly, the other person fiddles with getting the crows foot jammed against the nut as its turning. Its crappy but its the only way I have seen it done. Or, conversely, you can at anytime make this mod.

IMHO, no one should build an 8 with out doing this mod.


http://www.mstewart.net/super8/geartower/index.htm

I agree with the mod.

I will probably be flamed for my method but you do what you got to do. I shove my arm down the unmodified hole in the gear tower and shove a wrench on the nut. Several of the nuts are too close to the outside wall and I jam a flat screwdriver between the steel plate and the nut. I then have a helper tighten the bolt from the outside. Of course torque values are meaningless here. Its pretty obvious when a bolt has loosened and needs to be tightened.

Karl

Kahuna said:

IMHO, no one should build an 8 with out doing this mod.

Click to expand...

I agree. That was one of the two best modifications I made to my -8. Just for others' reference, here are photos of mine. Thanks to Kahuna for the initial motivation to do it, too.

(In case you're wondering, the other highly useful mod is/was an access door outboard of each rudder pedal. I'm just getting started on that one.)

BuckWynd said:

(In case you're wondering, the other highly useful mod is/was an access door outboard of each rudder pedal. I'm just getting started on that one.)

Click to expand...

I'm not sure I really understand this. Putting an access panel on the left side would be handy, especially if you have an Airflow Performance fuel pump there.

But putting one on the right side would just access the lower part of the forward baggage compartment, unless your also making the mod that extends the baggage compartment floor straight across and doesn't drop down to the floor of the a/c.

RV8N said:

putting one on the right side would just access the lower part of the forward baggage compartment, unless your also making the mod that extends the baggage compartment floor straight across and doesn't drop down to the floor of the a/c.

Click to expand...

Yes, that's what I'm doing. Sorry I forgot to mention that.

Access from both sides is also nice if you have brake reservoirs mounted on the pedals -- helps a lot when you service and inspect them, especially if you're a 6-foot, 220 lb. kind of guy...

Any way you can...

Bubblehead said:

I'm working through the first condition inspection on the RV-8 I bought, and need to check the torque on the landing gear bolts. I removed both access covers so I have access to the bolt heads, but how in the world do you get at the nuts in the towers?

Click to expand...

I made the mod in the gear towers like others mention here, but I still can't use any appropriate tools on the nuts because of their location. They're too close to the outside walls to get a socket on them, and the U-channel prevents the use of a wrench. I even had to grind a small flat on the hardened washers to prevent them from interfering with the outside walls.

Check out this link: http://www.romeolima.com/RV8/Fuselage.htm. Look at the 9th picture down the page and the associated text. Too bad I didn't see this before I drilled the holes, because it most definitely would have helped. I think I could have fit a socket on mine if I had used the 3/8" dimesion that Randy talks about instead of the 3/16" dimension. But alas...

I just reached the 10 hour mark on my RV-8, and I decided to torque these bolts like the manual recommends. I'm glad I did, because I was able to get at least a full turn out of each one of them.

I found that an allen wrench is a perfect tool for this job... Turn the bolt so the flat on the nut is parallel with the U-channel. Then find the allen wrench that will just slide into the space between the inside of the U-channel and the flat on the nut. Then take a straight-blade screwdrive and wedge it between the allen wrench and the U-channel to make the whole thing really tight. Then have someone torque the bolt from the other side.

Like an idiot, I tried making an aluminum sandwich of just the appropriate thickness to slide into the gap and prevent the nut from turning. Of course, the hardened nut just cut a groove right into the aluminum.

There are several threads here and on the RV-list that discuss this topic. All of them pretty much say the same thing -- use whatever you can to get the job done. But some extra nuts too, because when you grind all the points off the originals while experimenting to find the proper holding method, you'll need some new ones.

-Geoff

Geoff said:

Check out this link: http://www.romeolima.com/RV8/Fuselage.htm. Look at the 9th picture down the page and the associated text. Too bad I didn't see this before I drilled the holes, because it most definitely would have helped. I think I could have fit a socket on mine if I had used the 3/8" dimesion that Randy talks about instead of the 3/16" dimension. But alas...

Click to expand...

It's been a while, but I guess that's why I don't remember having too much problem tightening my bolts. Still tight though, and I agree with the gear tower door mod that Kauhuna describes, if I were building another -8 (you never know) that's what I'd do.

Photo needed

It would help me if I had some pictures of the landing gear bolts in the towers. In other words, the nut on the bolt. If I could see a couple of pictures I'd better understand how to hold the nut while torquing the bolt.

Even a couple of construction pictures would help.

Thanks,

John

What I found that worked was, I took a socket and ground down one side so the socket was in the shape of a almost open C. use a 90 degree swivel with an extension, 6-9 inch. Took less than 15 min to check the torque.

Chris Santschi RV8 N627CS
Festus,MO
EAA 1424 Tech Counselor

Thanks

Chris - thanks for the hardware advice. I'll try that.

John

3/16 or 3/8 inch??

I'm just about to do this step this evening - in great fear and trembling!! So I was very interested to read through this thread. I think I'll make the mod for the access panel - but the big question I had was "has anyone actually used the 3/8 rather than 3/16 measurement as suggested and if so how did it work out?

"Check out this link: http://www.romeolima.com/RV8/Fuselage.htm. Look at the 9th picture down the page and the associated text. Too bad I didn't see this before I drilled the holes, because it most definitely would have helped. I think I could have fit a socket on mine if I had used the 3/8" dimension that Randy talks about instead of the 3/16" dimension. But alas..."

I don't want to be the first to try it if it's going to be a dud!!

Thanks

Chris

Friday night my friendy IA (Ed) and I worked on the bolts. I took out the front seat back, laid the cushions down to provide a place to lay, and then stretched out to try and get to the nuts. On three of them a 9/16" open end wrench got enough bite on the nuts to allow Ed to torque the bolt. They all took about 1 turn to come up to spec. The fourth one was really hard to get on and we did not get quite to spec and started rounding off the flats so we quit.

The next steps are to modify a socket as suggested earlier, and to weld some small blocks onto an old 9/16" wrench to try and get more purchase on the nuts.

I tend to look for corrections to root problems rather than cobbling up "work arounds" like modified wrenches. It seems to me that the root of the problem is the ridge that blocks access to the nuts. Another IA buddy looked at the nuts and suggested using a slightly longer bolt and three washers to raise the nut so it is accessable with a wrench.

Since the bolt is in shear not bending I think it's a structurally sound idea. Any comments? BTW I'm a mechanical engineer so have some good education and experience to draw on but know the value of getting opinions from other knowledgeable people.

John

More info on a way to torque these bolts

I made a socket like Chris mentions in his posting but used square stock and a open end wrench instead of the swivel and extension. It's really the same thing as Chris did, if I understand him correctly. Here's a link to the posting with pictures.

http://www.vansairforce.com/community/showthread.php?p=181281#post181281

It would help me if I had some pictures of the landing gear bolts in the towers. In other words, the nut on the bolt. If I could see a couple of pictures I'd better understand how to hold the nut while torquing the bolt.

Click to expand...

If you cannot get a spanner in there, not sure how you'll get a camera in

20 hours on new RV-8 on bumpy grass.... and thinking we need to do just this

Andy & Ellie Hill
RV-8 G-HILZ http://www.g-hilz.co.uk

no real tricks to the shot

I was very surprised I was able to get a good picture of that area too! I think there were two keys to it.

1) take the pilot's seat back out so you can lay down across both seats and get comfortable.

2) use a pretty good or better camera with Macro setting and flash

I used a pretty good Nikon 3.1 mp digital camera, took 5 or 6 shots and of course tried to hold very steady so the camera could get a good reading on the distance and exposure.

I have pretty good shots of all four bolt locations. When I first took them I was amazed how much dirt and debris had gotten in their after 400 hours of flying time. I've been in there a lot with the vacuum and still have not gotten it all out. I hate to use an air hose because you never know where the dirt will go. Maybe an air hose and the vacuum at the same time?

After reading the posts from the last few years on these bolts, I was very concerned about mine. The previous owners were not very interested in maintenance. As I said elsewhere, all four bolts required a lot of tightening. The best of the four took 1/2 turn but the others were probably a turn or so from proper torque.

I solved that problem by simply making a small steel wedge. I position the
wedge between the bolt head and the weldment (rear side for tightening,
forward side for loosening). Of course you still have the problem of the torque
wrench being on the nut instead of the bolt but.......... it'll get you close
enough. Mine have not been loose in 3 condition inspections.