As the title says, the ACR fell out of the head on my rear cylinder. I don't have the tool to install a new one so I took the head to my local HD dealership to pick up a new ACR and have them install it. While there are still threads visible in the head, they recommended that I replace the head. They said that after they come loose like this, applying torque to the new one will strip any remaining threads, or best case, it will hold for a little bit but eventually fall back out.

Has anyone else experienced this and been able to successfully replace the ACR after it fell out?

 

Bullshit! Take it to a machine shop and put a Helicoil or a Timesert in it. Much cheaper and stronger than the original threads. I've had one in my truck for the last 12 years and 185k miles.

 

Do you think a Helicoil or Timesert is necessary? There are still threads there, it's just a question of if they can hold the 180 in-lbs (15 ft-lbs) of torque that's needed and if the ACR will come back out.

 

Perhaps Locktite has a product for this app.

 

I would timesert it and be done with it.

 

loctite does have a high temp thread locker..

LOCTITE 271

 

or half *** it and do it again later.

 

The service manual already calls for Loctite 246 Medium Strength/High Temp. You don't think it would come loose again?

 

Maybe your bike was built at the end of the shift on a Friday and they just overlooked the Loctite on that particular part. I'd re-Loctite it, torque it to specs, and let it cure out following the instructions and see what transpires!

 

Or take the chance of being 600 miles away from home in BFE with a dangling ACR.
Fix it right and forget about it