Hey Guys and Gals,

Need some advice. I replaced the speedo gear housing with the one from 914Rubber. While trying to put 13mm bolt back in I noticed it wouldn't go anymore and was not all the way in. Backed it and found little pieces coming out.

Here's a pic of the aftermath:
Click to view attachment

Is that a heli-coil? I have zero experience with heli-coils. How to best proceed? I do not want to damage anything.

Here's a pic of the 13mm bolt:
Click to view attachment

Thanks in advance!

retap the bolt and gently try again?

The helicoil threads are boogered. I remove and replace these with Time-serts. Since the hole is already opened up, I use the over sized ones. Once you install the insert, you will want to clearance the parts protruding into the speedo drive bore. I use a round file and patience so I dont gall or otherwise score the bore and cause a leak. This is a common failure.

Dr Evil,

Thank you for the advise. Some questions because I know next to nothing about time-serts or even helicoils for that matter.

"Since the hole is already opened up, I use the over sized ones." - Does this mean I just need to remove the helicoil then insert an oversized time-sert? No drilling or rethreading? What is the specific size Time-sert I should use? Obviously this would be easier with the transmission out of the car but I dont want to make things worse. I'll definitely will need to remove the muffler.

I assume the gear housing would need to be removed first. Do these ever just become stuck in the bell housing? Any methods other than wiggle and pull to remove?

I really do appreciate any advice I can get. I'm trying real hard to NOT destroy this transmission.

Thanks
James

This was also the reply I messaged you, but can put it here for reference for others.

The angle drive should slide out, sometimes takes effort, an open ended wrench, and a hammer to persuade it out. You would need it out to repair with most time-serts. You could try a shallow one, but I cant guarantee it will be enough threads to keep it from spinning.
Below I will link a video that explains the process of using a time-sert. You can buy the kits on Amazon. You will need an 8x1.25mm and would need to measure the depth to get the right part. I dont recall off the top of my head.
When you install it, and the angle drive is out, you will be installing a cylinder into a perpendicular cylindrical bore ( the bore where the angle drive inserts). As such, it will protrude in the center a bit and needs a rat tail file to knock it down. If you can find an insert that is just short enough not to protrude, good on you.

I recommend the larger bore insert as once you pull the helicoil there will be a larger hole than a standard time-sert will seat in. I recommend also using the drill bit and seat facer with a tap handle and and not in a drill. Go slow, correct your angle as you go, and it will turn out fine.

https://www.youtube.com/watch?v=anjDQJtWFc8

Thanks Dr Evil.

I will take pics as I go which may be awhile. Awaiting some parts.

Cheers!