Broken Bolt Nightmare
Rennlist Member
Joined: Oct 2012
Posts: 2,432
Likes: 204
From: California
Should have proofed my post, thank you and it's corrected. I've used them quite a few times on my old 928 and they are really easy to use and a high quality solution.
Last edited by Chalkboss; Mar 2, 2022 at 10:30 PM.
Rennlist Member
Joined: Mar 2017
Posts: 1,235
Likes: 436
From: Central CT
Late to the party, but I have BTDT many times, and could have told you the bolt would look the way it did after hearing that it was turned half a turn before sticking.
Don't get heroic here. Clean the threads on the bolt or replace the bolt. Run a tap into the hole. Reuse the cleaned bolt if you can get it to bite. It probably will.
Timesert is a good answer, but should not the be the first answer.
Don't get heroic here. Clean the threads on the bolt or replace the bolt. Run a tap into the hole. Reuse the cleaned bolt if you can get it to bite. It probably will.
Timesert is a good answer, but should not the be the first answer.
Last edited by 4Driver4; Mar 7, 2022 at 12:56 PM.
Racer
Joined: Dec 2008
Posts: 426
Likes: 17
From: Kingston, Ontario, Canada
Yup, run a tap through the hole (by hand, stopping every couple of turns to turn counter-clockwise half a turn or so and then continue until you hit bottom) and clean it with break clean and compressed air. You might then try a bottoming tap (has full threads on it) as I assume it's a blind hole. Then, purchase a new bolt from a industrial fastener shop of the same diameter, thread pitch, length and grade (bring the old one with you) and try the new bolt in the the reconditioned threads. If there is a lot of slop and play in the threads, perhaps a thread insert is the way to go. Or, if you feel lucky and think the other surrounding bolts will suffice, put some removable Lock tight on the new bolt and send it home.
A thread insert would probably be the correct way to repair it as it looks like the threads in that aluminum case may be ruined. You can buy thread inserts with larger external threads and the internal threads would be your bolt size and they will screw right in with a large screw driver due to the slots cut into the top of the insert. You will need to drill out the hole to the correct size for the exterior threads on the thread insert, tap the new hole with the correct tap then install the thread insert. However, you will need to check that there is enough metal in the case to allow the larger thread insert to be installed.
A thread insert would probably be the correct way to repair it as it looks like the threads in that aluminum case may be ruined. You can buy thread inserts with larger external threads and the internal threads would be your bolt size and they will screw right in with a large screw driver due to the slots cut into the top of the insert. You will need to drill out the hole to the correct size for the exterior threads on the thread insert, tap the new hole with the correct tap then install the thread insert. However, you will need to check that there is enough metal in the case to allow the larger thread insert to be installed.
