Cessna 120-140 Association

Hello all.
Thanks for any help in advance. I did read previous post on the subject and became confused regarding the necessary paperwork to do this correctly.
My 120, SN9734 has all four 5/16th bolts, and has extensions as well.. I want to replace with the solid Grove Axles and remove the extensions. They said they do offer the axles with all four bolt holes 5/16th. (no need to drill) They also offer AN hardware kits, instead of using MS sheer bolts??? (not sure I like that).
I spoke with them today, they said they do not offer an STC. They said this is done via field approval. They did have some examples of the 337's used for field approvals in the past.
Any suggestions on the proper bolts to use and field approval process?

Mark

The AN5 bolts are equivalent in strength to the original NAS144/MS20004 bolts. Don't give it a second thought.

Get the FSDO to sign off on the 337 before you spend money on the axles.

(Is there something wrong with your current axles?)

Thank you John for your reply,
I do not think there is anything wrong with my current axles. I am about to start the annul and I have never done a die penetrate inspection on them. Just a visual. I intend to remove the extensions and replace the bolts this year. I thought I should replace the axles since I have no info in the logs that indicate anything other than they are 76 year old. Ha. What advise do you have? Should I go to the trouble of getting a field approval? Never done that.

Personally, I wouldn't replace them unless there is a good reason to. I'll be 76 soon and hope no one thinks that's a reason to replace me!

Getting a field approval has a lot to do with how well connected your IA is with his PMI. If you want to move forward, talk to your IA first. If he (she, etc) isn't enthusiastic about doing it, I'd forget it.

Thank you John, Metal becomes old, people become seasoned! I'm right there with ya man.
Thank you very much for your advise sir.
MH

I replaced mine back in 2018. The P/N is grove 5016-2 for a 46' 140, I also put new bolts in. The axles are $90.00 ea. I found one with a hairline crack on the bottom side radius using dye penetrate, didn't bother with the other one. This may be the better option at shop labor of around $80-$100.00 hr. and you're already there with the axles removed. My 2 cents.