Stripped threads in crank for flywheel bolts. Question about Helicoil

[anumeric]

Well like the topic says the threads on my crank where the flywheel bolts in go to are stripped. I came across Tyrannix's old thread about the same issue he had. zerothread?id=197138 So I know I have a couple of choices of a fix. After checking out the webpages for both Helicoil and Time-sert they only make the correct thread in 15mm lengths. The stock flywheel bolt is 30mm in length from the tip - head, and 20mm of that is threaded. Can I just use 2 helicoil inserts by basically stacking em and breaking off the tangs after installation and cutting off any excess length if there is any. Sorry if this is a dumb question but I have never used helicoils before. And Helicoil and Time-sert has yet to answer my emails about the availablity of different lengths not mentioned on their webpages. Any help or insight is very much appreciated.

Thanks in advance, Wei

[themadscientist]

every hole is stripped?!

[Bwana]

Is the crank flange deeper than 15mm? You for sure don't need more helicoil than you have flange...

[Woods Crasher]

I had this problem with mine too. Here's what I did

1. Drilled out the broken bolts tap the holes to 7/16 x 20. 2. Drilled out the holes in the flywheel to 7/16 as well. 3. Bought some 7/16 x 20 1 inch long grade 8 bolts from boltdepot.com. 4. Slathered some jb weld on the threads for insurance, torqued them down.

Been good for about 5 months now. Just replaced my tired stock clutch for a spec stage 3 last week and every bolt is perfect. Perhaps I didn't need to jb weld them but I was pissed haha

*edited for clarity*
Modified by Woods Crasher at 5:49 PM 9/5/2007

[r34 gtr]

^ sounds like the proper way to go about it to me. Screw that helicoil junk, just drill and tap.

[Bwana]

I had this problem with mine too. Here's what I did

1. Drilled out the broken bolts tap the holes to 7/16 x 20. 2. Drilled out the holes in the flywheel to 7/16 as well. 3. Bought some 7/16 x 20 1 inch long grade 8 bolts from boltdepot.com. 4. Slathered some jb weld on the threads for insurance, torqued them down.

Been good for about 5 months now. Just replaced my tired stock clutch for a spec stage 3 last week and every bolt is perfect. Perhaps I didn't need to jb weld them but I was pissed haha

*edited for clarity*

Modified by Woods Crasher at 5:49 PM 9/5/2007

That should do it. I hope you never have to take it off though...

Loctite FTW.

[r34 gtr]

Wasnt that impressed with loctite to tell you the truth, my subwoofer managed to rattle some loctited bolts loose, as did my suspension. Tell you what really works though, put a little dab of gorilla glue on there instead. ITS DA ROC!!

[Woods Crasher]

That should do it. I hope you never have to take it off though...

Loctite FTW.

Nah they came out fine...Just gotta break them loose and they come right out...

[anumeric]

every hole is stripped?!

from the looks of it at least 3 of them

Is the crank flange deeper than 15mm? You for sure don't need more helicoil than you have flange...

Good call Bwana, I finally had the chance to pull the motor out and got a measurement on the depth and it was only 15mm, so I was kinda jumping the gun a bit. I had assumed that it was at least equal to the threaded portion of the bolt.

But thanks for all the responses and suggestions guys!

Wei