How loose is too loose for exhaust flapper

[squidtone]

Hi there,
My engine has developed a noisy "TAP" RAP type of sound, an obvious exhaust leak at the manifold area. I checked the usual suspects, and eventually I could feel a blast of exhaust leaking by the gasket where the exhaust and intake manifold are bolted together. I figured I had to replace the gasket. I took the works off, but found no leak, but saw to my dismay that there is jet black soot coming out of the shaft where it pierces the casting and holds the flapper. It's pretty loose. I can shift it side to side maybe 0.025". Still, I have a hard time believing it could make that kind of racket.
The wear is in the shaft seemingly. Not so much the casting (or what appears to be some kind of bushing perhaps)

I guess it's too loose and worn, but would you agree it would allow that kind of noise to escape?
Ugh. I don't think it looks to easy to replace that shaft.

[Rus Curtis]

I was hoping someone with a flat head would jump in on this.  I've read a bunch of posts about it and it seems to be a task.  Here are a few of those posts:

https://www.thecj2apage.com/FORUMS/back-of-manifold-heat-control-valve_topic47808_post484249.html?KW=heat+riser+repair#484249
https://www.thecj2apage.com/FORUMS/leaking-heat-manifold-valve_topic1779_post10886.html?KW=heat+control+valve+bushing#10886
https://www.thecj2apage.com/FORUMS/heat-control-valve_topic9980_post79779.html?KW=heat+control+valve+bushing#79779

The soot you describe was perhaps displayed in one of the posts above.  It doesn't sound like a weekend job to me. 

Here's the kit from AJP mentioned above.  I can see what looks like bushings.

https://www.armyjeepparts.com/p-322-heat-riser-rebuild-kit-exhaust-manifold-636439k.aspx

It would be nice to be able to source just the bushings if everything else works well.

[scoutpilot]

One should not assume the shaft isn't worn.

[SteveKfl]

For the price shown in the link Rus provided, IMO... it only makes sense to follow Scott's comment... and with the amount of labor involved... to replace it all.  You wouldn't want to do it twice.  You can always make available any useable parts for others that may be "missing" the flapper and/or return spring set up.  My L-Head did not have the set up at all, and has plugs in the shaft holes???  But I live in way South Florida, its original and whole life's usage area, and it hasn't been needed like with elsewhere and colder temps.

[squidtone]

Hi thanks for the responses...I've been away (Cape Cod) for a vacation, hence the delay in responding...
I must sheepishly admit that I may have gotten it a little bit wrong...I took apart the manifolds and discovered two of the 4 bolts were a bit loose...and there was suspicious black soot in the rectangular gasket in the portion that faces toward the center of the Jeep, that is, the passenger side. See the picture of the gasket.
Rather than stop here however, I decided to keep going and fix the sloppy flapper shaft.
I've been getting hit with a ton of little fixes in my "fleet", something like death by a thousand cuts, so I decided to cheap out and go minimal in my repair. I only needed a shaft and maybe bushings. I didn't want a (ultimately after shipping) $50 dollar kit. I bought a shaft only from QTM. In a nice February 1955 manila envelope.

I tried drilling out the weldment on the original flapper but it was too hard. I ended up using an ancient dremel tool with a 1" cutoff wheel and ground the weld down to the shaft. It went way quicker that I thought. See the picture of the ground out weld (still in the manifold). The shaft was easily tapped out after grinding.
See picture of worn shaft. Yep, it was really loose and I'm sure contributed to the noise.
I put in the new shaft, lined it up, and welded the flapper to it in place. The original shaft bushings are not perfect, but ok. It's much tighter now. All good.
I put the bimetallic spring back , smacked the shield on, then the counterweight, and snugged it in.
New gaskets, buttoned it up.
Nice, NICE, nice and quiet now...I think the quietest it's ever been. Ahh the joy of the classic Go Devil fan noise is far above the noise floor now.
Thanks for your comments!

[Rus Curtis]

Sounds like you got multiple issues sorted out and got a smoother engine.  Nicely done!