Anyone ever had to drill out a snapped torque converter bolt??

sb001 · 04 April 2018, 15:06

Ugh-
SO here's the whole story-
As you may have read in my other thread, I recently had to remove the clutch servo canister from my car due to no shifting into gear from neutral, idle surging etc. Figuring it was the canister diaphragm, I went about removing the canister- but when I knocked out the hinge pin between the clutch arm and the servo canister arm, guess what happened- that's right it fell RIGHT DOWN into the bell housing window!!!

Which of course means pulling the whole damn engine to retrieve it.
So I set about doing that yesterday-- got the pin out, but NOW when I was putting everything back together, when I went to reinstall the torque converter bolts, tightening them down to spec (18 ft/lbs) I snapped the head off one of them!!

$:-\$
So now I have the threaded part of that bolt stuck in the flex plate... is there any way I can drill that out and/or extract it while still in the flex plate, so I don't have to remove the engine again AND remove the flex plate? The other 3 TC bolts seem to be holding everything just fine BTW... but I don't want one loose side of the TC screwing anything up...

Dave · 04 April 2018, 16:34

All I can think of is drilling a line across the top of the thread using a Dremel tool or similar to turn it into a flat headed screw suitable for a flat headed screwdriver.

sb001 · 04 April 2018, 16:52

Quote from: Dave on 04 April 2018, 16:34
All I can think of is drilling a line across the top of the thread using a Dremel tool or similar to turn it into a flat headed screw suitable for a flat headed screwdriver.

The problem with something like a Dremel is that whatever tool I use has to fit through the hole in the tab of the torque converter-- none of the remaining bolt is actually sticking through the tab any longer- it broke off beneath that tab. It's all JUST in the flex plate. So when I said I snapped the head off, I should have said I snapped off the head and a tiny part of the threaded "stem."

I think I'm almost going to have to use some sort of extractor bit... if I can get a drill up into that tight space. Something like this maybe?:

https://www.lowes.com/pd/Kobalt-Screw-Extractor-Set/999957791

68autobug · 05 April 2018, 01:52

I just answered this on the other post.... but You need to use a drill as large as You can so there isn't much left of the screw. Then use an extractor the correct size, as I tried to extract a bolt once and I just drilled a small hole in the bolt and the screw extractor broke off... I bought titanium drills but they wouldn't touch the screw extractor... they are too hard... I have used High tensile hexagon headed allen screws and even 8.8 grade hexagon headed bolts. I think I had to grind a spanner or socket to undo them... so far I have never dropped a screw into the bell housing... I don't think driving with 3 screws in the flexplate is a good idea... be careful as the nuts on the flexplate can came off too... and the flexplate is balanced..

Lee in Australia

sb001 · 06 April 2018, 01:56

Thanks Lee-

I'll see what I can do about it when i get a chance.

Here's a look at what I'm up against...

68autobug · 06 April 2018, 04:34

Hi sb001,
it has been a long time since I was under My car , but it's good that You can actually see the broken screw. You will need a drill with a flexible shaft. You can get small dremel sized drills with a flexible extension. So, You need to drill out as much as the old screw as possible, so the extractor can just unscrew what is left.... mostly just the thread. I would look at replacing the 4 screws with high tensile allen headed screws which are much stronger... You will probably have to cut them to length and file the end so the thread goes into the nuts neatly...

cheers Lee in Australia

paulheger · 06 April 2018, 08:47

OMG what a job.
Are you going to execute with the engine attached or take the TC out?

Good luck!!

sb001 · 06 April 2018, 19:59

I'm going to try it as is first, with engine still installed... I just need a straight shot into that broken bolt to drill and then use the extractor tool... I think I can get it without having to remove everything but we'll see. I've watched a few youtube videos on peole using these extractor tools- doesn't look too tough as long as you don't break the extractor tip off in the screw--if I do that then I am royally screwed. I'll just try to go slow and take my time...

sb001 · 09 April 2018, 02:15

Well after mulling it over I changed my mind and decided to pull the engine today:

Will make it WAAYY easier to get that broken bolt out now:

and there are other related things I've needed to do for awhile now anyway like clean up the engine, replace the tarboard in the engine bay, etc... Plus while the car is out of commission it might motivate me to get some other jobs on the list done as well, like finally replace the headliner, install the new seat covers I have, replace the cracked dash pad, etc etc etc

68autobug · 09 April 2018, 09:50

Well, that is now much easier to fix the problem. Don't forget to replace the torque converter seal....

LEE

68autobug · 09 April 2018, 13:38

Hopefully the original bolts weren't too hard [too high tensile] as they will take some drilling... maybe a normal drill won't be able to drill it?

Lee

paulheger · 09 April 2018, 15:10

Where are you going to get a new bolt?
Are you all using the same kind of bolts as original applied or are replacements from DIY shop? (if so what specs to look for?)

sb001 · 09 April 2018, 17:51

These were aftermarket replacement TC bolts I got from somewhere-- don't even remember now. Probably made in China crap. They are definitely NOT the original German TC bolts-- the originals were sharpened to a much finer point on the 6 points around the hex head and had an extra grooved washer plate around the bottom of the head:

This is the kind I had:

The OEMs were probably much higher tensile strength as well, and the reason 18 ft/ lbs is fine for them but may be too much for the replacements I had.

sb001 · 09 April 2018, 17:57

Quote from: 68autobug on 09 April 2018, 09:50

Well, that is now much easier to fix the problem. Don't forget to replace the torque converter seal....

LEE

You know, I have only ever replaced my TC seal once, that was several years ago- and I don't seem to have a problem with it even after removing/ reinstalling my engine several times since. However, I did pick up a new TC seal at the VW show last fall for a song-- guess i might as well use it.

Hooper454 · 11 April 2018, 00:28

I just purchased torque converter bolts from evwparts.com. Have not received them yet to see what they look like. (4.95 each). Two of mine the bolt head stripped even with a 6 point impact socket. (Using a hand ratchet). Had to use a pneumatic hammer with a 2ft pointed tip and CAREFULLY get a bite on the side of the bolt head and got them turning. Then a socket to remove them the rest of the way. I would caution anyone attempting this, it takes a steady hand. one slip, and you could go right though the torque converter.

As I posted in another thread, someone had been into the clutch before. They could have used a cheap socket and or over torqued the bolts. 18 ftlbs is not much. A little hard to get your torque wrench up there!

You can see on one of the bolts where I was able to get a "bite" and start the bolt turning.

Also forgot to mention. In your case with the bolt head broken off, you might get a sharp pick and see if the bolt will turn. With the head missing and threads not stripped. Sometimes they will turn right out.