Timing chain tensinioner rail bolt
#1
Timing chain tensinioner rail bolt
So my timing chain guides broke so got everything apart correctly and I started putting it back together, and as I was putting the bottom left guide bolt to hold the guide in place, and it must have had a crack in the thread and I broke the thread part of the bolt off in the hole. I have tried an easy out but the threads are gone. It's stuck in there so I have tried drilling it out but it will not stay strait. Any ideas or advice? Anybody done this before this problem has had my Mini down for 3 weeks already and it's driving me nuts. Please help!
#2
Get a Heli Coil kit. I had to do it one one of mine. You should be able to pick one up at your local auto parts store. My bolt was an M6 verify yours. Don't over torque it. Use blue loctite on the bolt after. Create a guide that you can slip into the hole to keep your drill bit straight to get out the bolt. Good luck.
#3
It is very difficult to drill a straight hole by hand, try making a jig to direct the drill bit precisely into the sheared off bolt. The broken bolt will sometimes back out on its own if you drill it out with a reverse twist drill bit. If there is any of the broken bolt protruding from the hole, you can weld a nut onto the broken end of the bolt and turn it out with a wrench.
If the broken bolt is already messed up from trying to extract it, you will have to drill it out with an oversized drill bit and jig and install a helicoil or other thread insert system.
If the broken bolt is already messed up from trying to extract it, you will have to drill it out with an oversized drill bit and jig and install a helicoil or other thread insert system.
#4
#6
Drill a hole of few cm, use counter-clock threading heli coil, then put some quality bolt and torque it. Being counter clock, it will take the stuff out.