What's new
Van's Air Force

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

Preventing Rod End Thread Corrosion?

avrojockey

Well Known Member
Patron
Heres what I pulled out of my rudder yesterday while doing another repair...

IMG_1149.jpg


Seems to be galvanic corrosion from the reinforcement plate, rudder horn and rudder spar. I pulled the other heim bearings and they had the same thread corrosion but not as bad as the lower bearing.

Im replacing the bearings but would like some thoughts on preventing future occurrences. I'm leaning towards and annual spritz of CorrosionX to weep down the threads.
 
Antiseize

I would think a good anti seize would better. One and done?

Also, why is the plate touching this? Is the clearance hole not big enough, or is it off center?

If it is just junk building up in the hole, I again go back to my antiseize to fill up that spot. JMHO YMMV
 
Last edited:
If you are grounded waiting on this part you are welcome to come grab some from my not-yet-flying RV10. Just let me know which part # and I'll confirm I have them handy.
 
If you are grounded waiting on this part you are welcome to come grab some from my not-yet-flying RV10. Just let me know which part # and I'll confirm I have them handy.

Mighty fine of you, but ACS-Midwest is back open now after their "COVID cleanse" and I can get them by Tues. I have enough to occupy my time til then.
 
Also, why is the plate touching this? Is the clearance hole not big enough, or is it off center?

If it is just junk building up in the hole, I again go back to my antiseize to fill up that spot. JMHO YMMV

I checked the clearance and it was good. I also checked the construction manual and hole is suppose to be drilled to 3/8"...it looks like it was (I'm not the builder).

I think anti-seize sounds like the ticket, and tef gel looks promising...I'll just stay away from jam nut portion of thread for proper torque.
 
Last edited:
Are you sure that's corrosion Tim? It looks a lot like what I generally see on lower rudder rod end bearings as an accumulation of belly oil and dirt. On almost every RV tail dragger, you're going to get dirt accumulating on whatever oil/lubrication is there.

Just asking because I have never seen corrosion on those things - even when I lived in a salt air environment - but I have seen lots of grime....

Paul
 
I'd like to see what it looks like cleaned up - it is hard to see if the threads are corroded / damaged, or just caked with gunk like others have mentioned.
 
Are you sure that's corrosion Tim? It looks a lot like what I generally see on lower rudder rod end bearings as an accumulation of belly oil and dirt. On almost every RV tail dragger, you're going to get dirt accumulating on whatever oil/lubrication is there.

Just asking because I have never seen corrosion on those things - even when I lived in a salt air environment - but I have seen lots of grime....

Paul

I thought that was the case at first but the picture is AFTER I took it to a wire brush then to a wire wheel on the bench grinder. Its definitely corrosion. Anyway at only $16 a piece its worth replacing all of them on a flight control.

Interesting though is the lower rudder fairing didn't have a drain hole in it per plans and water had collected in it. I wonder if the lower bearing being in close proximity to it had anything to do with the corrosion being worse.

BTW...fully enjoyed your webinar a couple weeks ago!
 
My $.02 is this was from a loose nut which allowed the rod end thread to fret in the nutplate. I would check the threads in the nutplate as well.
 
makes me think the tie rod material is not very good. very good find. was this aircraft ever stationed by the sea?
 
makes me think the tie rod material is not very good. very good find. was this aircraft ever stationed by the sea?

Not near salt water that I know of.

I was able to scrape off the paint and read part# and they're the original Van's supplied Aurora bearings (Heim clones) also available at ACS...

https://www.aircraftspruce.com/catalog/appages/aurorabearings.php

I wonder if the quality is not the same as the Heim brand. They're a lot less expensive than the Heim equivalent.
 
I helped with a commercial flight test aircraft 10 yrs ago. A supplier had substituted aurora tie rod ends for heim because of availability. the aurora tie rod ends failed after a year. there was a lot of corrosion. your finding is more proof for me. poor material quality.
 
A little history

Not near salt water that I know of.

Hi Tim,
The second owner of your aircraft lived near Pensacola but I don?t know how long 904DC stayed there before going to Texas and Kansas. I bucked a few wing rivets, witnessed the first flight and have about 10 hours in her before she was sold by the original owner/builder. I was glad to see her being flown a lot after you got her.

Again, I don?t know if she stayed long enough in Florida to initiate what appears to be galvanic corrosion on that rod end bearing. I do note that the paint scheme on the tail has been changed from the original checkerboard red and white so her rudder skins may have been changed along the way as well.
 
Hi Tim,
The second owner of your aircraft lived near Pensacola but I don’t know how long 904DC stayed there before going to Texas and Kansas. I bucked a few wing rivets, witnessed the first flight and have about 10 hours in her before she was sold by the original owner/builder. I was glad to see her being flown a lot after you got her.

Again, I don’t know if she stayed long enough in Florida to initiate what appears to be galvanic corrosion on that rod end bearing. I do note that the paint scheme on the tail has been changed from the original checkerboard red and white so her rudder skins may have been changed along the way as well.


Looks like the second owners only had it for 6 months, then it went to Dallas/Fort Worth area for 5 years, then Evansville, Indiana for 6.

Yea...it had some down time for awhile, but I've put about 60 hrs on it so far, mainly commuting for work. It's been running good for 1300TT. I was fixing some cosmetic things when I found a gnarly hole had been drilled through the rudder horn and spar for the tail light. We didn't catch this on the pre-buy. :( The replacement parts were inexpensive from Vans and I have a lot of free time with work being slow, so it wasn't a big deal to fix...and I get some new tools! This is when I pulled the rod end bearing and found the corrosion.
 
Last edited:
QUOTE: "Seems to be galvanic corrosion from the reinforcement plate, rudder horn and rudder spar."

Galvanic corrosion should have eroded the aluminum, not the steel. Something is weird though. It could be as rocketbob said, or mouse urine, or poor quality, or other unusual incompatibility.

Glad you found it. This is why we inspect.
 
I had rudder rod ends frozen on my 8. The ball was frozen in the heim and the bolt frozen in the ball. Had to saw the ends in half to get the rudder off the plane and grind off the head and nut to remove the heim end from the rudder.

Have been to the Bahamas twice, a multiple short coast trips and multiple sun-n-funs over the 12 years before it happened. All other the other heims are OK. No other aircraft corrosion issues and heims were spray lubed annually. With the bolt on mine frozen in the ball maybe there is some type of dissimilar material problem with these ends.

FYI, the ECK corrosion lube is available from spruce.

George Meketa
RV8
 
I lube my exposed aurora rod ends with LPS1 every other flight. this will not slow galvanic corrosion.
 
Last edited:
Back
Top