Broken Motor Mount Bolt
01-25-2009, 12:22 PM
#1
Broken Motor Mount Bolt A friend and I are in the middle of installing a set of Poly Motor Mounts on his 98 Z28. Things were going pretty well, until we twisted off the drivers side lower rear 13mm mount to block (clamshell) bolt. We're taking a break to eat some lunch. After we finish, we plan to remove the drivers header and see what kind of room we can gain. If anybody has any advice on how to safely and properly get the broken bolt out of the aluminum block, we're all ears. Thank you...
02-04-2009, 10:56 PM
#2
No one seems to be interested, but I thought I'd give this thread an update.
A couple days after twisting off the bolt, I started drilling into it with some cobalt bits. I couldn't get the best angle with my Dewalt Drill. The K Member was in the way to really get centered on the bolt. So I drilled as deep as I thought I could without getting into the threads. Next I drove a bolt extractor into the hole and began to turn it ccw into the bolt. I had a really good bite, and thought now was the time to put some muscle to it and get this bastard out. So I got a good grip and twisted that ****** hard. "SNAP!" Yeah thats right. I busted off the easy out in the bolt. So not only do I still have a bolt stuck in the block, but now a Hardened Steel bit. ****. I tried drilling at it. Nothing. So after a few days of asking friends, guys at work and anybody who'd listen, I was searching the net for ways to bust through an easy out and found a testimonial on a yachting website. A guy had a similar situation and he had used a Dremel with diamond tipped bits to eat the bolt/bit away. I thought what the hell, I'll give it a shot. The gentlemen claimed the stuck bolts were dust in like 5 min. Well my experience wasn't exactly 5 min. More like 5 hours each day for a couple days and 4 or 5 bits later, I had the easy out and bolt ground away enough I thought I could start drilling again. By this time I had an arsenal of drills borrowed and a 90* air powered one that really did the trick for fitting into the tight spot. Started drilling again and "ting." The tip of the easy out came flying out. YES! I then proceed with the 90 to drill completely through the bolt, progressively using larger bits. Then rather than risk busting off another extractor, I decided I would drill the bolt out as large as I could go and then use a tap to cut new threads. I stayed up until 3am last night working on this, but I'm happy to its done. The motor mounts were installed this afternoon with minimal fuss and now all thats left is to return everything to its spot in the engine bay and finally finish the exhaust. If everything goes well should have the project completed by Sunday. Wish us luck...
A couple days after twisting off the bolt, I started drilling into it with some cobalt bits. I couldn't get the best angle with my Dewalt Drill. The K Member was in the way to really get centered on the bolt. So I drilled as deep as I thought I could without getting into the threads. Next I drove a bolt extractor into the hole and began to turn it ccw into the bolt. I had a really good bite, and thought now was the time to put some muscle to it and get this bastard out. So I got a good grip and twisted that ****** hard. "SNAP!" Yeah thats right. I busted off the easy out in the bolt. So not only do I still have a bolt stuck in the block, but now a Hardened Steel bit. ****. I tried drilling at it. Nothing. So after a few days of asking friends, guys at work and anybody who'd listen, I was searching the net for ways to bust through an easy out and found a testimonial on a yachting website. A guy had a similar situation and he had used a Dremel with diamond tipped bits to eat the bolt/bit away. I thought what the hell, I'll give it a shot. The gentlemen claimed the stuck bolts were dust in like 5 min. Well my experience wasn't exactly 5 min. More like 5 hours each day for a couple days and 4 or 5 bits later, I had the easy out and bolt ground away enough I thought I could start drilling again. By this time I had an arsenal of drills borrowed and a 90* air powered one that really did the trick for fitting into the tight spot. Started drilling again and "ting." The tip of the easy out came flying out. YES! I then proceed with the 90 to drill completely through the bolt, progressively using larger bits. Then rather than risk busting off another extractor, I decided I would drill the bolt out as large as I could go and then use a tap to cut new threads. I stayed up until 3am last night working on this, but I'm happy to its done. The motor mounts were installed this afternoon with minimal fuss and now all thats left is to return everything to its spot in the engine bay and finally finish the exhaust. If everything goes well should have the project completed by Sunday. Wish us luck...
02-04-2009, 11:12 PM
#3
Good luck, man. Sorry to hear about your troubles. I will be doing my poly's soon because my Y-pipe is banging the underside of the car after I changed my oil pan gasket two weeks ago. It always banged a little, but it's much more prominant now.
Any tips on the job you can give me? I had taken off the passenger mount when doing the oil pan, but I haven't tried doing the driver's side. It looks like there's even less room on that side. Do you think I should definately take off the driver's header or do you think I can work around it?
Any tips on the job you can give me? I had taken off the passenger mount when doing the oil pan, but I haven't tried doing the driver's side. It looks like there's even less room on that side. Do you think I should definately take off the driver's header or do you think I can work around it?
02-04-2009, 11:21 PM
#4
When we started this project, we had already installed the headers and decided we would try to complete it without taking them off. But once we broke the bolt, we needed all the room it would allow to get a drill in there. So we removed the drivers header and left the passenger side alone. It took alot less time to remove than I thought it would. (The header that is.) We just pulled the plug wires then the plugs and then the header, leaving the coil packs in place on the valve cover. I would say pull the drivers side for sure. And as for other advice, read the thread entitled, "best poly motor mount install thread ever." Or something like that. Thats the info I used, and it was wonderful. Good luck.
07-07-2009, 02:11 PM
#6
We did consider that option as a last resort, but decided if you're gonna do something, do it right and be done with it. This way it doesn't come back in the future to bite you in the ***. I've done two more poly mm installs since then without any trouble. It being a bitch the first time made the next couple times seem like a breeze.
07-08-2009, 08:45 AM
#7
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Nah. Instead of half-assin' it, I used my whole ***. LOL
We did consider that option as a last resort, but decided if you're gonna do something, do it right and be done with it. This way it doesn't come back in the future to bite you in the ***. I've done two more poly mm installs since then without any trouble. It being a bitch the first time made the next couple times seem like a breeze.
We did consider that option as a last resort, but decided if you're gonna do something, do it right and be done with it. This way it doesn't come back in the future to bite you in the ***. I've done two more poly mm installs since then without any trouble. It being a bitch the first time made the next couple times seem like a breeze.
