Stripped oil screen bolt

[buztabuzt]

Old Yamma twin. Oil and filter change as usual. Had been a few years since I looked at the oil screen thats at the bottom of the oil pan (slightly below drain bolt. Held on by 6 tiny 8mm bolts and a gasket. In past it had some small metal flakes so wanted to give it a look. Looked good

Went to reattach with torque wrench set to 10 ft-lbs. Torque wrench worked fine for drain bolt and filter bolt. Something went wrong at such a low setting. I kept spinning it and was surprised it hadn't clicked off. I kept spinning (gasp), despite thinking something was off.

Now I have half a bolt that dropped out, half stuck way in there. Naturally it stripped the threads in that area. So... I assume best practice would be to remove the half a bolt somehow (seems too deep / small for EZ out) and retap it? Would it be terribly ill-advised to leave it and see if it just holds a seal assuming I don't need to check that screen anytime soon and know I need to keep an eye on it/oil level?

TLDR: Can i leave stripped half bolt in bottom of pan? It's one of 6 bolts holding on a screen housing. I added couple hundred CC of oil last night to see if it drips (not under load).

 

[CaptChrome]

I wouldn't leave a broken bolt in the case, but that's just me. I have seen others do a lot worse than leave one broken bolt in an engine though.

It would take some careful drilling and a small EZout to get it out. Not a fun job, especially with the engine still in the frame.

 

[JPaganel]

Left handed drill bits.

They can be hard to find - I've had guys at hardware stores get mad because they thought I was messing with them. But they are totally a thing, and if you are trying to drill out a blind screw they are what you need.

https://www.amazon.com/Comoware-Dri...9Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

 

[buztabuzt]

I wouldn't leave a broken bolt in the case, but that's just me.

Yep.... It leaked slowly through what remained of the bolt. No lazy way out of it for me. Thanks!

 

[tstidham]

Another option is to drill and tap the case oversized and get a stepped stud in there. The bolt thread should be 6mm and they make studs with 6mm on one side and 8mm one the other. I would then use either red or green locktite to hold the stud in the case.