Oil Jet Bolt Hole Thread Repair
 

This is just a quick post to document my experience and confirm that the oil jet bolt hole in the block can relatively easily be repaired using a helicoil type repair.

I didn't come up with this solution, I found all the info on this awesome site from some clearly knowledgeable folk.


Okay, so long story short, I stripped the oil jet bolt hole in my block and the severity of the implications of this f*ck up (is swearing prohibited?) saddened me greatly.

I've done a lot of searching and most people either suggested getting a new block, re-tapping the same thread and using thread lock, but very few suggested a helicoil solution. I wanted the more permanent solution that would put my mind more at ease so helicoil it was.

As people know the oil jet bolt is an M8 x 0.75 thread pitch. A metric size that I don't believe is available with any helicoil type repair kits.

However there is a very similar imperial size that is available. 5/16 x 24.


I didn't need to ream/enlarge the hole as the ally block is soft enough and my entire length of thread in the block was gone.

- I used a 300mm long ratchet tap wrench, re-tapped the hole using the tap that was included in the thread repair kit of the imperial size mentioned.
- Cleaned out the swarf as best as I could, inserted the helicoil type insert using the tool and initially pliers for the extra reach.
- CAREFULLY re-threaded the oil jet bolt using a 5/16 x 24 die bought separately. The size and pitch of this thread is almost identical to M8 x 0.75 so the bolt will still have decent usable thread over its entire length.
- Put the jet and bolt back in and torque the bugger down to 12 ft/lb / 16 NM.

Job done.

And if anyone is interested;

5/16" = 7.9375mm

:tipwink: :thumbup: Well done sir! I'm sure that bit of knowledge will come in handy.

I know someone that got the exact metric size repair kit from an Australian supplier, he is the only one I know who has one. I don't know the exact supplier other than he had to bring it in from Australia.

Good info but not sure how if it's that hard to find the correct thread pitch.
First hit on google http://www.threadtoolsupply.com/M8x0...epair-kit.html
Another one from Europe http://www.jgengineering.ie/products...l-kit-helicoil

Ahh good find! For some reason when I did a search I couldn't find the right metric size. Those aren't exactly cheap either.

At least for those who will attempt this in the future has options.