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How to fix oil leak from pulled stud - oil pump shaft bearing.

I have recently purchased and installed a 1977 2.7 engine in my 914-6 that had a top end rebuild. The long (about 3") stud that clamps the bearing on the oil pump drive shaft and exits towards the bottom of the case approximately below the distributor - see pic, appears to have been over-torqued and has stripped the threads to the point that it can't be tightened correctly. I know the correct fix requires splitting the case and machining in a time cert/equivalent etc. I read comments that suggest this stud is not critical and unless the engine will be highly stressed (competition driving), I should wait until the next time this engine is rebuilt. The stud "bites" the stripped threads a little - more than finger tight. I have used this limited tension to apply some gasket paste along with a fibre washer and two nuts to lock them together holding this attempted temporary fix. It has reduced the oil leak significantly but not satisfactorily. I am thinking of removing the stud, thoroughly cleaning with detergent, blowing out debris and cleaning fluid to clean and dry. Then applying J-B Weld in a thin layer in the stud threads and a small blob on it's end, then inserting it back in place torquing it as much as possible and letting it sit for 24 hours. Then using an aluminum crush washer under a nylon lock nut. Good idea or bad? Other suggestions?

Old 01-12-2018, 08:51 AM
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Are the threads stripped inside the case? Is it the stud that's stripped?
Old 01-12-2018, 09:00 AM
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Mag cases pull that stud. You have to split case to case saver the hole
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Old 01-12-2018, 10:04 AM
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If you don't want to split the case, run a 10x1.25 tap in the hole and install a very short 10mm bolt with an aluminum washer. Done tons of them that way. No drilling needed. No damage done. It's not like that one stud is super important. Fix it with a timesert years from now if the case is ever split. You need to use a open end wrench on the tap because of limited space.
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Last edited by john walker's workshop; 01-12-2018 at 10:24 AM..
Old 01-12-2018, 10:13 AM
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Make sure it's a flat bottom tap.
Old 01-12-2018, 11:26 AM
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Actually you’re only tapping enough threads to hold a short bolt, so either Tap should be fine. You’re not tapping through the entire case into the other side.
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Old 01-12-2018, 11:38 AM
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Thanks John Walker. All clear except what do you mean by "very short" 10mm bolt, - just long enough when inserted with aluminum crush washer from outside the case so it tightens against the case before running out of the new cut threads?
Old 01-12-2018, 11:40 AM
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Oh, dummy me! I got it, and now a much easier tapping job - should not need more than say 1/2' of the bolt in case thread - so say 5/8" long to cover washer thickness should do it?
Old 01-12-2018, 11:50 AM
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Probably 3/4" long. You don't have to worry about the chips really, because the hole dead ends. Blow it out and don't reef on the bolt too much and strip the new threads.
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Old 01-12-2018, 01:03 PM
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Will report back, thanks.
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