RV 4 Aileron Hinges

[petrolhead]

Can anyone please tell me how to remove the bearings on my RV4 Ailerons. These are the spherical self aligning bearings fitted into bored holes on the laminated rib extensions about 6mm thick. The bearings are the same thickness as the rib. (2 x 3mm) The left hand outer aileron bearing has developed axial play but no radial movement. The bearings must be retained somehow but exactly how is a mystery. Also the retaining bolt (1/4") has seized on the inner race. Help please.

Petrol Head UK

[captain_john]

This is pretty much what you are looking at:



You need to remove these little buggers from the wing, or at the very least attempt to separate the halves and pry the bearing out. The design doesn't really lend itself to repair/replacement too easily, but it is possible.

Does this help?

CJ

[Wicked Stick]

CJ,

Great picture post.. I'm sure it will help...

I said to myself when I was building these... "how the heck can you easily replace the bearings" and then realized you can't "easily" do that once the whole thing is riveted together and mounted to the wing structure.

I'd say it would be very very prudent maintenance to keep them well lubricated to avoid the task at hand that now faces Petrol.

[petrolhead]

Thanks for the help. I thought that the job was going to be a bit of a b***** but could not really believe that the design did not allow for easy replacement. Will need to proceed with caution.

Thanks.

[dsb]

There is a blurb on page 361 of the '27 years of the RVator' (RVator 6/91) that shows the bearings being pressed in and out with a C-clamp and special tool...

I have no first hand knowlege, I just happened to be reading thru '27 yrs' and remembered this thread...

HTH,
Dave

[Spike]

Let us know how this goes for you. It could be an interesting learning point for us.


And kudos for David for his first post.


Spike

[petrolhead]

Following an exchange of information with Vans Aircraft it would seem that the only proper solution is to remove as many of the rivets as possible ** in the bearing housings and prise these open slightly, removing the bearing out from between the split. Extreme care must be taken as the plates must not be sprung too far apart as permanent deformation may occur. Re-riveting should re close the gap 100%. I intend to clean the bearing housing and apply the minimum trace of Loctite Bearing Retainer 638. Taking extreme care not to get any INSIDE the bearing. Stuff with grease first using the correct grade.

** rivets that you can be replaced without removing any Wing Skin Rivets.

Another Vans "suggestion" was to remove the hinge unit totally and replace with a new one. Unless the wing skin is coming off this is not a practical solution.

Another extreme option would be to leave the OUTER race in situ (assuming it is in good condition) and press out the worn spherical portion. It must have been pressed in when the bearing was made !! Then press in a new inner. !!! Not tried this one yet !! Watch this space.

[captain_john]

Personally, I would remove them ENTIRELY from the wing and replace them on the bench.

You could use Cherry rivets to re attach it, but I would use solid ones.

Taking a few rivets out of the corner of the lower wing skin isn't a bad option of you need to do that.

CJ