uh oh: pulled case fastener stud by oil cooler

[Baby]

I am one torqued through bolt away from finishing the case reseal. While loosening the last bolt, the stud pulled. I am being very careful not to disturb anything or create shavings of any kind. I can't pull it all the way out. So do I have any options here other than to split the case? Any way to repair it in situ?

[304065]

The good news is that this happened now and not once you had the engine together.

The case must be split and the pulled stud repaired with an insert. To install the insert requires that you remove the old damaged threads and drill the case. This is not possible with the case assembled, and even if it were, chips would go everywhere.

[Baby]

Good news, indeed. Thanks for your reply. Time to make an appointment with the machinist.

[Flat6pac]

There is well over an inch of threads there. Yiou cant possibly have pulled an inch of threads with 25# of torque.
I would put some loctite on a fine thread 10mm nut with a couple turns on the threads, let it harden and run it in to seat. It should take all the threads and get firm in the torque. Pull it out, put some loctite on it and run it in to the bottom.
If you found good threads, which you should, you can torque to spec and not open the case.
Bruce

[Baby]

Thank you, Bruce, for the suggestion. I should have been more clear in my initial post. The stud is inserted in the insert and that it's the insert that was pulled. The insert looks like it will just about fit through the hole in the case, but it gets hung up. I can thread it back where it belongs about three full turns before I hit dried loctite or whatever is in there. Probably with some kind of collet I could go deeper, but I don't think I could get loctite on the insert threads, and I'm inclined to open it again, have a look at what's going on, and make sure everything is clean in there. That said, I'm open to suggestions.

[Baby]

Well, I obviously didn't know WTF I was talking about with the insert. There is no insert. It was just the stud that came unglued and unscrewed from the case. I don't see any damage. I chased the case threads, and the stud threads nicely, though it's a bit wobbly without sealant. I think I just need to clean the case threads, add glue, and thread it in. What kind of sealant holds the stud in there? The remnants are white and rubbery.

It's the one on the top that came out...

[ajwans]

What did you chase the thread with?

andy

[Baby]

I grabbed the chaser I made for the head stud threads, which is an old head stud with a channel cut across the threads. The threads for the head stud are I think thinner than those for this stud, so it's not an exact fit, but it fit in nice and easy, and it was enough to cut the sealant that was in there so I could test fit the stud. I'll get in there with some brake cleaner and a bore brush to get all of that stuff out before I loctite the stud in there for good.

[Walt Fricke]

I'd be tempted to use red Loctite. The only reason I can think of for having to remove this stud ever is if you needed to line bore the case. And by and large no one has to do that with the aluminum cases. And even then, you could get the stud out.

I suspect few of us have ever seen one of these studs get loose. I haven't on the half dozen or so different motors of mine I have had apart one or more times.

[Baby]

Thanks, Walt. That's what the machinist recommended as well. Hoping to clean things up today and get the case back together early this week.

[Baby]

After several tries to get the right perimeter studs from Pelican, I chased down what I needed at the local VW hot rod shop and finally got the case together. I'm thrilled to report there are no oil leaks so far. Thanks all for your help and guidance.