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Oleo troubles!

Posted: Sat Jul 25, 2020 8:49 pm
by norcal64d
Currently working through the first annual on my MX-7-180 and after topping of the oleos, I noticed they are leaking. I pulled the right side out this morning to change the o-rings and I was amazed to see the oleo strut rod was actually bent! I dissembled the oleo assembly and the last 1/3 of the rod is pretty clearly bent as you can see in the picture. I see two options, either a new heavy duty spring assembly or replace the rods in both sides with new o-rings. Any thoughts? Is it correct that the new heavy duty springs will need to be machined down to fit?

Also, the top NAS shear bolt holding the strut to the frame was bent slightly, it was in the airframe for 8 years and maybe 500-600 hours, so the recommendation of replace every two years seems worthwhile to me.



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Re: Oleo troubles!

Posted: Sun Jul 26, 2020 5:31 pm
by maules.com
I wouldn't trust that connecting tube so suggest new from Maule. Measure your unloaded spring length and call Maule for new spring lengths (i don't have my info where I am) Get matched length springs. If your new springs don't fit the diameter (depends on year your oleos were made) it is fairly easy to file to correct diameter if you don't have lathe access.
Be sure the 4 oleo cylinder holes are not elongated and deburr inside of holes to aid in O ring insertion. Inner O ring needs lube and smoothed chamfered connecter tube end to prevent O ring damage.

Re: Oleo troubles!

Posted: Sun Jul 26, 2020 6:12 pm
by norcal64d
I'll be calling the guys at Moultre to get some parts ordered in the morning. I think this is a good time to do that upgrade to the new springs they sell. My only concern is should I be worried about the soft bushing that this oleo rod goes through? It doesn't seem like there is much play between the two, but not sure if they have to replaced together to prevent slop. Good tips on the orings, thanks. Left side oleo appears to be totally fine for what its worth.

EDIT: Not sure if people have seen the inside of these so I took some pictures that might help someone else take theirs apart. My spring is 29 years old so a newer one might be different but it only expanded about 3/16" of an inch once the three bolts were moved on the bottom sleeve.



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Re: Oleo troubles!

Posted: Sun Jul 26, 2020 7:08 pm
by Mog
If it were me, I would just spring for two new Oleo Cartridges. Just get the full assembled guts with matching springs. It’s a bit expensive I guess but worth it to have all fresh new components. I’m not big on throwing stuff away, but sometimes it worth it.

Re: Oleo troubles!

Posted: Tue Jul 28, 2020 6:51 am
by norcal64d
Mog wrote:
Sun Jul 26, 2020 7:08 pm
If it were me, I would just spring for two new Oleo Cartridges. Just get the full assembled guts with matching springs. It’s a bit expensive I guess but worth it to have all fresh new components. I’m not big on throwing stuff away, but sometimes it worth it.
I was debating about doing that and ended up just pulling the trigger on the two new assemblies. More money up front but a good strong landing gear is worth it.