Torque Coverter Bolts Sheared
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Joined: Oct 2020
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Torque Coverter Bolts Sheared
Hi all,
I recently replaced the engine in my 2004 Civic EX, and reused the old transmission. The new engine came with the flex plate still bolted on, so I used that instead of taking off the old one. I finished the swap, and everything seemed fine. I was able to drive for 20 miles or so, until getting off the freeway I lost all power. Car would not restart, only starter spinning. I figured I would need to replace the starter in order to diagnose whatever the other problem might be, but while I had the starter removed, I noticed I could spin the torque converter by hand, and I could crank the engine by hand and see the flex plate spinning separately from the TC.
I opened up the one of the shift cable covers and 5 sheared-off bolt heads dropped out. I think there's 8 bolts, so I hope they're in one of the other covers, rather than floating around in the transmission somewhere.
Has anyone experienced this before? What might have casued this? Should I not have reused the flex plate that came with the new engine? Should I have bought new TC bolts? I see now the installation method is to put the bolts in hand-tight in a crosswise before tightening all the way. I just tightened them as I spun the crank and the holes came into view. Was this a fatal error?
How f'd am I now - new TC? Flex plate? Entire transmission? Seems one way or another I would need to drop the trans - either to drill out the remnants of the bolts either from the flex plate or TC where they sheared, or to replace the flex plate/TC/trans as necessary. Is it even worth it to try to save anything, or should I just get a whole new (used?) trans and start over? Definitely with Loctite on these damn bolts next time.
Thanks!
I recently replaced the engine in my 2004 Civic EX, and reused the old transmission. The new engine came with the flex plate still bolted on, so I used that instead of taking off the old one. I finished the swap, and everything seemed fine. I was able to drive for 20 miles or so, until getting off the freeway I lost all power. Car would not restart, only starter spinning. I figured I would need to replace the starter in order to diagnose whatever the other problem might be, but while I had the starter removed, I noticed I could spin the torque converter by hand, and I could crank the engine by hand and see the flex plate spinning separately from the TC.
I opened up the one of the shift cable covers and 5 sheared-off bolt heads dropped out. I think there's 8 bolts, so I hope they're in one of the other covers, rather than floating around in the transmission somewhere.
Has anyone experienced this before? What might have casued this? Should I not have reused the flex plate that came with the new engine? Should I have bought new TC bolts? I see now the installation method is to put the bolts in hand-tight in a crosswise before tightening all the way. I just tightened them as I spun the crank and the holes came into view. Was this a fatal error?
How f'd am I now - new TC? Flex plate? Entire transmission? Seems one way or another I would need to drop the trans - either to drill out the remnants of the bolts either from the flex plate or TC where they sheared, or to replace the flex plate/TC/trans as necessary. Is it even worth it to try to save anything, or should I just get a whole new (used?) trans and start over? Definitely with Loctite on these damn bolts next time.
Thanks!
Honda-Tech Member
Joined: Jun 2017
Posts: 30
Likes: 2
Re: Torque Coverter Bolts Sheared
Service manual says to tighten them in several steps in a star pattern, I believe to 12nm. Been a little while since I did one of these but my guess is you didn't torque them properly to spec and follow the procedure so it was out of whack, causing the bolts to break. Did you hear any strange noises when you first started it up?
Good news is you can get a reman torque converter for about $100 on eBay. I think that's all you'll need to replace unless the flex plate is damaged, in which case it sounds like you have an extra anyway. Also if you didn't before, now would be a good time to take off the flex plate while you have the trans out and make sure your rear main seal looks good.
Good luck man. I doubt the trans itself or engine is fucked because of this.
Good news is you can get a reman torque converter for about $100 on eBay. I think that's all you'll need to replace unless the flex plate is damaged, in which case it sounds like you have an extra anyway. Also if you didn't before, now would be a good time to take off the flex plate while you have the trans out and make sure your rear main seal looks good.
Good luck man. I doubt the trans itself or engine is fucked because of this.