Wing Removal

[Rick]

It looks like we will be removing the wings from my 2007 DA40 during the annual this year. A couple of the nylon rollers that the aileron pushrods run through are cracked (one on each side, of course), and apparently the only way to replace them is to remove the wing and then remove the pushrod. As far as I can tell from the logbooks, the wings have never been off before. Does anyone have any suggestions from past experience on other things we should consider replacing while it's apart (fuel tank hoses, tubing, etc.)?

I've also just hit 2000 hours, so there will be a static bonding check due this year, too. I'm afraid this is not going to be such an easy annual...

[Steve]

Rick:

You may not have to remove the wing. I have replaced 3 of these rollers in my 2001, 2 of which were in the wing. See:

viewtopic.php?f=8&t=4260&p=55373&hilit=Roller#p55373

Unfortunately, the photos seem to have vanished from Photobucket, but I still have them on my computer. I'd be happy to send them to you or post here. It took me about 2 hours to replace each roller in the wing. The one in the rear of the fuselage took less time. You don't have to remove the pushrod. It isn't a fun job, but takes a lot less time than pulling the wing.

Steve

[smoss]

Steve, how is the one in the rear of the fuselage easily replaced? It seems like the whole elevator pushrod would need to be removed. Alternatively, it seems like an individual roller could easily be removed from the assembly by snipping the axle rivet, then simply putting a new roller in its place with a new rivet. Is that what you did?

[Steve]

Yes. Only one of the rollers was cracked in each assembly. You could theoretically replace all three rollers in the assembly by this method, leaving the frame riveted to the bulkhead. It is tough working in the wing! I used a Dremel grinder to remove the head of the axle rivet before driving it out. Then used a cap screw and nyloc nut to install the new roller.

Steve

[Rick]

Thanks, Steve - that is very helpful information! I would be very interested in your pictures if you still have them. Funny, I have no recollection of that old thread - even though I replied to your post in it - or I would have searched for it first!

I see in your other post where there is a SB from Diamond to add access panels in the wings to make the replacement easier. Has anyone done that yet? If so, how difficult was it to add them, and did it help?

[Karl]

We have added the panels, it makes it a lot easier to replace the rollers.
Not difficult to do but worth getting a good composite guy to do it so that you get a nice clean finish.

[Colin]

Can you feel the cracked rollers? Or is it just found on inspection?

[Steve]

Can you feel the cracked rollers? Or is it just found on inspection?

Colin:

In my case, there was no change in the control 'feel'. My three cracked rollers were found during Annual Inspections. You have to use a light and inspection mirror for the ones in the wing. A couple of the roller assemblies are almost "un-inspectable" due to their location on the side of the wing rib facing away from the inspection hole. The ones in the fuselage which support the elevator pushrod are easier to both inspect and repair than the ones in the wing.

Steve

[Rick]

Same with mine - I can't tell a thing from the controls, but they were noticed during an inspection through the wing access panels. The cracks don't appear to go all the way through the nylon roller, but look like surface cracks to me. I wonder what the effect of a roller cracking all the way through would be, though. I am trying to conceive of a situation where the nylon surface somehow comes off and sticks between the pushrod and the metal roller housing and wondering if that could sufficiently jam the controls such that you could lose aileron control. That just doesn't seem possible given the amount of pressure you can apply via the pushrods, but on the other hand that would make for a very bad day, so I suppose they need to be replaced.

I asked Diamond about it, and they said they recommend replacement, but it's at the discretion of the A&P. They also confirmed that there is no need to remove the wings to replace the partially-accessible rollers, but the ones on the other side of the spar require cutting the new access holes. They also sent me the work instructions for the new access holes - if anyone needs them just PM me.

And, in case anyone cares in the future:

The roller guide part number is: DS-RG3.
The rivet for the roller guide is: DIN7337-A4.0x10.2-A2

[RMarkSampson]

I pulled my wings off my DA-20 for the 1000 hour a few years ago - amazingly easy to do. If you do pull your wings, recommend you purchase new bushings for the ailerons and flaps hinge points and replace all the bolts/nuts - they are out in the weather, not expensive and likely need replacing depending on the age of your aircraft. Flipping the wings upside down on a table makes working on the ailerons and flaps really easy to do - just use a few furniture pads to keep things soft w/o scratching the top part of the wing. Waxing the bottom of the wing is also 1000% easier when it is on top.