I noted some binding of the carb heat control during a recent flight. When I pulled the air box to check the shaft bearings, I found the upper skin has a significant crack in it. A new air box for the C180B, P/N 0750126-21 is $8.8K! I found a reference that the 0750126-21 can or has been superseded by 0750144-33, although Yingling’s website doesn’t reference this. However, the upper skin for the latter box, P/N 0750144-28, is avail for ~$350, and looks like it can be made to work by joggling the aft rivet line of the new part and cutting out from that portion forward on the old part. I can’t find a listing for the upper skin for the original part number. Does anyone have any experience with this or another repair?

Get in touch with Randy Rubbert. He rebuilds Air boxes, better than new and reasonably priced. You’ll never have to rebuild it again. (701) eight fower seven 3 008.

MTV

Wilco! Thanks!

mtv wrote: Get in touch with Randy Rubbert. He rebuilds Air boxes, better than new and reasonably priced. You’ll never have to rebuild it again. (701) eight fower seven 3 008. MTV

THat's good to hear.
A buddy had Atlee Dodge overhail his 180 airbox some years ago and it was crazy expensive.
What's to keep your regular A&P from just bending up some new pieces and rebuilding the airbox?

Another friend just had to replace the shaft bearings & seals in the airbox on his 182.
Bought the bearings from McFarlane, which weren't esp cheap,
but he said a replacement shaft was unreasonably priced.
He got some hardened round stock and fabricated his own.
Came out real nice.

Unfortunately, the upper skin would have been press-formed by the factory, so it’s beyond my A&P skills. I’ll call the rebuilder suggested by MTV on Monday, as well as Acorn Welding, Texas Salvage, Beagles and Dynamic Propeller (they sell SS upper skins, just not my P/N) and come up with a plan.

After closer inspection, it looks like my idea of adapting a later model upper skin won’t work as there’s not enough room on the aft end of the airbox to run a rivet line:

here’s a couple pics of the crack:





It appears that the box is made of a weldable alloy, as there appears to have been a weld repair previously:



Also, one seam seems to have been spot-welded:



Can anyone confirm from experience that these boxes can be TIG welded? If so, I’ll remove the top flange, and see if I can run a puddle on the crack.

I just had mine repaired at dynamic propeller because of a similar issue and several cracks. It was "reasonably" priced compared to other options out there. They also included the beef up kit with the repair. New side and top skins, shaft and rubber seal were about $1500. Only issue is there were a few gaps between skins and some toenailed and under driven rivets I wouldn't have let go. Not too bad but something I've been meaning to address with them. Its on the plane now and does work great after using a little high temp rtv to fill the gaps.

I used Dynamic Propeller about 10 years ago and was very disappointed. Their workmanship was poor, and the returned box was unuseable.
They said that was best their guy could do.

My IA and I took it all apart and he put back like new. He even had to cut a new rubber flap to fit better.
I had supplied a new shaft and bearings.

The original top was all good, and the only cracks were in two of the filter flanges, and one had been previously repaired. All I got for my money was the two flat flanged pieces. The heat duct inlet fell off in the box coming back.

Worst service ever.

BTW, be careful of using sealant after the filter.

I used "The Air Box Doc" - Joe Rogg. My airbox was trash, and Joe completely rebuilt it, box, flapper, etc. Gave me a very fair price - and did the 2 STC's from Dynamic Propeller. It was about as close to new as you could get - and even better then new with the STC's.

https://www.barnstormers.com/ad_manager/ad_detail.php?ID=326455 that is the add he uses has on barnstormers.

FWIW, we've had good luck reassembling the top flanges with PRC in between the skins. Its absorbs a lot of the vibration and helps keep them from cracking again.
I dont have a good source for a new top skin, just thought I'd add what has worked for us.

corefile wrote:….and did the 2 STC's from Dynamic Propeller. It was about as close to new as you could get - and even better then new with the STC's...........

Curious as to what the two STC's entailed.

A new stainless top skin is available from Cessna. The advantage of the new skin are the formed angles that pick up the sides unlike the old skin or some of the aftermarket replacement skins as mentioned. This is a common place for them to crack.
Atlee dodge can weld a new flange and neck on the new Cessna skin. It makes for a very nice repair.
Atlee Dodge has done a few airboxes for me and all have turned out better then new. They also have a few rebuilt ones that’s a basically brand new but very expensive.
This is the last one I rebuilt with the new top skin with welded neck.

I like the isea of putting a second upright support on the airbox on the other side.. I think that helps eliminate vibration of the airbox.
Gary

The other thing that really improves longevity is to install better bushings/bearings in to support the shaft. I can’t recall what Randy uses, but the air box for my 170 came back far better than new, and I know guys who have literally thousands of hours on theirs with the shaft still tight and smooth.

MTV

Here’s what I have so far:

Acorn Welding- $3600 max, no FAA paperwork, 2 wk turnaround.

Randy - too busy doing Super Cub airboxes, has a lifetime warranty, would do it only if I couldn’t find anyone else. No numbers discussed. Did say cracks can be TIG welded, but weld is not as durable as a new skin.

Texas Air Salvage - no stock at present. Maybe next week, as they have some new salvage coming in.

Joe Rogg - voicemail full. Will try again later.

Atlee Dodge - will call at 0900 AK time.

hotrod180 wrote:

corefile wrote:….and did the 2 STC's from Dynamic Propeller. It was about as close to new as you could get - and even better then new with the STC's...........

Curious as to what the two STC's entailed.

The two STC’s from dynamic propeller that I added to my rebuild from Joe Rogg was
1) Stainless Steel top skin (this includes the airbox brackets - so if you buy this your get the Airbox bracket STC as well)
2) Air box bracket kit
They are the ones found here:
Airbox STC

This is all great information. I'd like to rebuild my airbox in the next few years. Thanks for sharing all of your experience folks.

What he said^^^

jrc111 wrote:After closer inspection, it looks like my idea of adapting a later model upper skin won’t work as there’s not enough room on the aft end of the airbox to run a rivet line:

here’s a couple pics of the crack:

While rebuilding, also take a look at Cessna SB 78-16 (I think that's the number). It may not specifically apply to your model year, but that SB discusses adding a third rivet to each side of the mounting collar for additional strength. From your pictures, I see you only have the original 2 rivets.

Chris

I'm amazed nobody has just come up with a fiberglass version of this box. It's not a terribly complicated shape, and mechanically really doesn't have a lot going on. It would also virtually eliminate cracking issues, and probably smooth out the airflow. I don't know what it would cost to STC such a replacement but it can't be any worse than the rest of the airbox STC mods out there.