No Back Clutch Spring Alternate Source?

[Lax291]

Hey All,

Doing some research on the no back clutch spring (https://mooney.com/wp-content/uploads/2020/12/SBM20-282A.pdf), it looks like these things are:

1) Controversial in thinking of replacing based on the Mooney SB or leaving alone as if it ain't broke don't fix it

2) Hard to get with long lead-times

3) Stupidly expensive

In my last annual they noted my spring was past recommended replacement time and I should start thinking about getting on the list to buy one.  After I picked my eyes up off the ground and popped them back into my head from seeing the price of this tiny spring, I thought there has to be another source.

So, I'm trying to see if I can find a spring manufacturer who can make these as I work to support industrial automation and we have a few spring manufacturers in my area.  Luckily, we are heavy into aerospace and defense in CT so these companies are already making parts for commercial and military aircraft. 

With that said, I am asking for this groups help to see if you think this effort would be futile or worthwhile?    I have put up a poll to see who might be interested in purchasing a spring if we can get them made for a much more reasonable price and to the same spec/quality.  I'll use this number as a basis for a small run if the manufacturer is able to produce them to get rough pricing to share with the group.

From the specification side, does anyone have documentation, drawings, or anything else that would be helpful for the manufacturer to review to determine if they can make the spring?  

If I'm being too ambitious and someone else has tried this before without success please let me know, I'm just hopeful there is another avenue and source to get these critical parts we need at a reasonable price.  Thanks for any help you can offer!

[Andy95W]

I suggest you add an additional option:

- Don’t currently need, but would purchase as a spare if available. 

[Lax291]

15 minutes ago, Andy95W said:

I suggest you add an additional option:

- Don’t currently need, but would purchase as a spare if available. 

Thanks for the suggestion, just added it!

[Greg Ellis]

Maybe add another option...."I have the greatest gear system ever made...A Johnson Bar... so I don't need no stinkin' spring." 

[toto]

The problem today is that it's far from  clear whether a replacement spring would be less likely to fail than the original spring.  I'm way over my 1000 hours on the original spring, and I still haven't seen a clear answer from the many threads on MS.  It seems there was a bad batch of original springs that drove the service bulletin, and also bad replacement springs that caused at least one recentish off-field landing.  And in any event, these things don't fail very often.

[Lax291]

13 minutes ago, Greg Ellis said:

Maybe add another option...."I have the greatest gear system ever made...A Johnson Bar... so I don't need no stinkin' spring." 

How does this additional poll option sound, "I've got a Johnson to grab, no BS needed"?

[LANCECASPER]

And maybe another option - won’t replace a perfectly good no-back spring for an unproven one.

Don Maxwell says listen to yours on a retract test and if it’s not noisy, leave it alone. They will “chatter” a long time before they fail.

[ArtVandelay]

I suggest you add an additional option:
- Don’t currently need, but would purchase as a spare if available. 

Put me in this column if it’s not stupidly expensive.

[Pinecone]

Someone already tried to develop an OPP spring.

Last I recall he needed a broken spring to do metallurgical testing to determine the alloy used.

[201Steve]

Please, someone needs to finally deal with this. Go for it.

Dont let any of the commies tell you it’s not allowed either.  They are not manufactured and there is no other alternative. Period. 

[Echo]

8 hours ago, Greg Ellis said:

Maybe add another option...."I have the greatest gear system ever made...A Johnson Bar... so I don't need no stinkin' spring." 

All hail the johnson bar.  All hail the johnson bar.  All hail the johnson bar.  All hail the johnson bar.  I will have a little salt in my wound please.  Thank you sir may I have another?  Did I mention...All hail the johnson bar?  Hey Greg, good for you.

[201Mooniac]

15 hours ago, Pinecone said:

Someone already tried to develop an OPP spring.

Last I recall he needed a broken spring to do metallurgical testing to determine the alloy used.

Used springs can be found at some MSCs.  I offered to hook them up with Mark at Top Gun who confirmed at the time he had used springs.  I'm not sure an OPP would work here though as each owner needs to be involved in the process and I doubt the spring manufacturer would produce them one at a time.  I would expect a PMA is necessary.

[Lax291]

Thanks guys, seeing some good interest just in the day of the post being up so I reached out to the first company to give them an idea of what I'm looking for, mentioning it might have to be through a PMA so I'll keep you updated on what they come back with.  I won't get overly optimistic, but would sure like a way to get this done for us.  Appreciate all the help, humor, and feedback so far!

[Pinecone]

On 10/3/2024 at 11:08 AM, 201Mooniac said:

Used springs can be found at some MSCs.  I offered to hook them up with Mark at Top Gun who confirmed at the time he had used springs.  I'm not sure an OPP would work here though as each owner needs to be involved in the process and I doubt the spring manufacturer would produce them one at a time.  I would expect a PMA is necessary.

Owner can do quality control by inspecting and measuring to ensure the part is in spec.

[201Mooniac]

1 hour ago, Pinecone said:

Owner can do quality control by inspecting and measuring to ensure the part is in spec.

Thanks, I didn’t realize inspection alone would be sufficient to count as an OPP. 

[Grant_Waite]

On 10/3/2024 at 5:32 PM, Lax291 said:

Thanks guys, seeing some good interest just in the day of the post being up so I reached out to the first company to give them an idea of what I'm looking for, mentioning it might have to be through a PMA so I'll keep you updated on what they come back with.  I won't get overly optimistic, but would sure like a way to get this done for us.  Appreciate all the help, humor, and feedback so far!

Lasar is currently acquiring the rights from Eaton to have the no back springs made. Eaton doesn’t want to have anything to do with the gear motors anymore. A 3rd party company was contracted to make them for Eaton. As you can imagine they only make large batches. I recently bought an Eaton from Lasar. I’ve spoken to Kyle at the repair department too many times to count. He’s told me they should have them available sooner rather than later. I would give him a call before you waste time and money. 

[LANCECASPER]

2 hours ago, Grant_Waite said:

Lasar is currently acquiring the rights from Eaton to have the no back springs made. Eaton doesn’t want to have anything to do with the gear motors anymore. A 3rd party company was contracted to make them for Eaton. As you can imagine they only make large batches. I recently bought an Eaton from Lasar. I’ve spoken to Kyle at the repair department too many times to count. He’s told me they should have them available sooner rather than later. I would give him a call before you waste time and money. 

It was mentioned at MooneyMax 2024 that Mooney International had licensed the no-back spring  to LASAR.

That's a much better solution than trying to re-invent the wheel. 

[201Steve]

4 minutes ago, LANCECASPER said:

It was mentioned at MooneyMax 2024 that Mooney International had licensed the no-back spring  to LASAR.

That’s great news! Yeah?

now we just need them to do the dukes gear set and we’ve solved a big problem!

 

And a quick note to the sick individuals who troll gear discussions like high school bullies. We don’t have the same airplane as you. Whatever possesses you all to continually enter discussions about normal (electric) gear systems and rabble rouse, I do not know. I suspect it’s a friendly “hey we are in the same club so I can give you a hard time”, but that’s the best I can come up with. It’s not original, it’s not funny, you’re the twelve millionth person to do it, we do not have the same airplane, and it is a very weird flex from the perspective of the troubleshooters you are targeting. You might as well join a helicopter forum and troll them for having tail rotors. That’s how ridiculous it sounds. 
 

We are just dealing with the problems applicable to our airplanes. You don’t see us entering your discussions about shitty dog houses and flexible intake plenums and trolling you bc we don’t have that problem. But maybe that would be funny.