Removing sheared converter bolt.

Post by **MattH** » Mon Jul 20, 15 12:28 pm

Has anyone managed to do this in situ?

I'm wondering if I can get an easy out and drill out the sheared bolt without having to take the transmission out for the second time this year.

Pete · Post by **Pete** » Mon Jul 20, 15 12:40 pm

Impossible on a Big Block, a lot depends on the shape of the rear of the sump on the small block.

How do you propose to drill it dead square in that scenario....you are just putting off the inevitable.

The bolts are grade 8 so drilling will be a nightmare and the drill will want to wander off..you may even end up needing a helicoil.....

Post by **MattH** » Mon Jul 20, 15 12:45 pm

How about driving it with three bolts?? It will make a noise but what is the worst, it loses drive?

Classics on the common Wednesday and Nats at the weekend. I don't really want to drop the box.

Pete · Post by **Pete** » Mon Jul 20, 15 12:55 pm

You pays your money.....

....I would be careful but at least it is a full plate and not one of the cheap and nasty stock ones.....I would not trust one of those...

I assume it is the tiny bolt version?

ANTON · Post by **ANTON** » Mon Jul 20, 15 1:57 pm

try undoing all the torque converter bolts and turn the flex plate so you can see the welded on lug and maybe then you can user a dremel cutting disc and put a slot in the stud and use a screw driver to get it out.

Demon James · Post by **Demon James** » Mon Jul 20, 15 3:42 pm

I managed to heli-coil a flex plate bolt in situ but I did have to take the sump off to get the drill square (very important)

I also used the tap in a decent battery drill with fine trigger control. Lots of gentle and patient forwards and backward turns. I also ground one of my heli-coil taps flat to do the last couple of turns once the correct one had cut enough new thread.

Be VERY careful not to drill too far

I did mine four years ago and check it now and then as its so easy to get to. No movement so far and that's 3 Nats weekends, two RWYB and Le Mans and back plus about 15,000 miles

Always worth a check though

Oh and a little dab of thread lock, all in all it took me about a hour but it wasn't in the least bit relaxing

Matt · Post by **Matt** » Mon Jul 20, 15 5:00 pm

Turn the flexplate like Anton says until it clears the sheared stud.

Then hold a nut over the stud (with pliers !) and Mig quickly through very hot.

Worked for me once on a flush-sheared (and tight) converter drain plug (Ford 460) . Oh and use an unplated nut of course...

Pete · Post by **Pete** » Mon Jul 20, 15 6:10 pm

ANTON wrote:try undoing all the torque converter bolts and turn the flex plate so you can see the welded on lug and maybe then you can user a dremel cutting disc and put a slot in the stud and use a screw driver to get it out.

The problem Matt has is that he has a full circle SFI-approved Flex Plate so there is no "Gap" to access the sheared bolt - it's not like a standard Flex Plate with "big gaps" to provide working access.....this is why I say it is either drill it out or trans out...........

Blue · Post by **Blue** » Mon Jul 20, 15 6:26 pm

I think your only choice is to carefully drill it and try an easy out. Has the bolt broken flush with the flexplate or right back in the converter lug?

Post by **MattH** » Mon Jul 20, 15 6:36 pm

It has broken in the lug so is below the flex plate, which is a full SFI one with no gaps. It has sheared due to coming loose and hitting the block so I am hopeful that it may not be too tight in there.
I will take a fresh look tomorrow morning ands see what access I have.
The thread is not currently damaged so I am hoping to undo what is in there and not have to tap any new thread.

At least it s not inside the engine this time. (well it wasn't last time I just didn't spot it til I had it all apart).

Pete · Post by **Pete** » Mon Jul 20, 15 6:43 pm

Knowing your luck you will get out of jail and manage to ease the stub out....the welding approach may still have some merit if you can get in there - all that extra heat may also help...

Post by **MattH** » Mon Jul 20, 15 6:55 pm

Pete wrote:Knowing your luck you will get out of jail ...

I hope you are right!!
I didn't feel like I had much luck today when I found it, but it did explain the noise and the rattle-ting-ting just before the noise started when I last drove it, as the bolt head got chopped off and bounced off the exhaust pipes onto the road.

Pete · Post by **Pete** » Mon Jul 20, 15 6:59 pm

You WERE lucky, you could have damaged the transmission case.....just look on the positive side, it will be better tomorrow..........

terryr · Post by **terryr** » Mon Jul 20, 15 7:10 pm

if it has worked its way out ,in theory the left over thread should only be finger tight,take the rest of the bolts out and the vertor should drop back a bit and I would bet it will come out with a tap round with a screwdriver

Post by **MattH** » Mon Jul 20, 15 7:32 pm

Hadnt thought of that Terry. Of course once all unbolted the converter has a bit of movement back and forth.
What time is sun up tomorrow, I will be there!