My annual is going on right now and my A&P asked if Maules have a chronic airbox cracking problem. He sent my airbox out for welding since it's had cracks the last several years and he has seen the same kind of cracking on other Maules. He suggested that I contact Maule and find out if the newer airboxes have a different design or construction that reduces cracking. I emailed Kasey at Maule Parts and she told me that she wasn't aware of any design or construction changes but that David was working on something related to airboxes.

A new airbox is $850 and 4-6 weeks for delivery. There are none in stock. I don't know if all the cracking would be reduced with a new airbox but I don't want to spend $850 only to find out that there's just as much cracking as my current airbox.

The shop that my A&P sent my airbox to has some ideas for strengthening it to avoid cracking.

What is the experience of other Maule owners?

Andy,

My M5-235C is down in Georgia near Moultrie for some major work. My IA has a good relationship with Maule and is over there often. He did mention that an improved air box is in the works. I did not get the impression that it was close to market though.

My air box is also in terrible shape, being original to 1977 and is being reworked with hope for the eventual availability of the improved design. So I guess I would say, repair versus buying another of the original design.

Kirk

On my M-5235C the airbox had been put back together many times. there were a lot of riveted on patches rather than welding it back together. It was in very rough shape to the point that I was thinking about building a new one myself. I ended up getting a new air box from Maule to replace it. That was a couple of years ago. I do not remember the new one being that much money. For 850 I would have probably made on myself. So far, I have not had any issues with the new one. I have to imagine that any air box lives a rough life. Work hardening and metal fatigue over time do not help.

Mine is cracked and patched extensively. A sexy carbon box replacement would be nice and fix the cracking issues.

My 1977 Maule M5-235C is in for annual. There is a good sized crack along the edge of the lower plate. Was not there at last annual. Several small cracks had been stop drilled. Plan to I plan to grind the rivets out and replace the lower plate. Looks like it is not unusual.

Jim

I may have an air box available. I would have to check when I get home tomorrow. Let me know if you are interested. I'm not sure if it's off a 180 or 235 though.

My M-5-235 airbox has cracked too over time, not terrible but it could be better.

Mog wrote: ↑

Mon Dec 18, 2023 4:01 pm

Mine is cracked and patched extensively. A sexy carbon box replacement would be nice and fix the cracking issues.

I’d think more economical to build and no chance of broken rivets going down the carb. The traditional boxes are very labor intensive.

Guess it’s an approval expense issue. Wonder what the Experimental Worl does?

Kirk

Kirk wrote: ↑

Mon Feb 19, 2024 9:51 am

[quote=Mog post_id=60357 time=<a href="tel:1702944070">1702944070</a> user_id=1911]
Mine is cracked and patched extensively. A sexy carbon box replacement would be nice and fix the cracking issues.

. Wonder what the Experimental Worl does?

Kirk
[/quote]

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