Alright guys, I’ve got a real problem here. I just got my transmission back from Calimer (stage 3 build) and I went to put the slave cylinder in and the bolt broke. I was using the original bolts that held the old slave cylinder, I felt the bolts start to get tight, but the slave cylinder was still loose so I kept going and it snapped. I was using a torque wrench set to 8 ft/lb and it never clicked so I definitely wasn’t expecting to break a bolt. I’m thinking my torque wrench, which I’ve used less that 5 times, may be bad. Only thing I can think of is that the cryo treatment that Calimer does made the hole shallower, hence why the bolt got tight, but the slave cylinder was still loose. I tried drilling into it and using a bolt extractor, and of course that broke off inside too.

Has anyone ever had an issue like this or have any ideas on what to do next? Only thing I can think of is to bring it to a machine shop on Monday.

 

You could drill the bolt out and tap it for a new bolt

 

I’ve been trying that, but the bolt extractor that is broke off in there is very hard, not having any luck getting through it. I went to Home Depot and bought some “hard metal” drill bits and still can’t get through

 

Try some heat also that may work while you drill. Also use a cutting oil while drilling that helps. You will go through some bits so dont get attached to them.

 

Ive never heard of cutting oil, I’ll have to see if I can find some tomorrow

 

You could use wd40 as cutting oil

 

Got it all done today. Started with a 3/16” drill bit, with some “Dark Thread Cutting Oil”, wasn’t making much progress. Found a video of a guy using a hole saw bit (typically used to drill holes in tile or granite) so I ran to Home Depot and picked up a couple. Those were working well, ended up having to run back for a third, but got the job done. Those bits aren’t cheap, about $15 each, but we’ll worth it. Evened the hole out with a 15/64” drill bit and used an M7 tap to make threads. It was an all day project that required 4 trips to Home Depot, but gladly the job is done and the slave cylinder is in! 😁

 

That's good news, never thought of using a hole saw bit. Make sense though normal ones are usually only good for wood. I have used this method at work more times than I can count. Glad to hear you got it all done and back in working order. Good job.

 

I’m glad it’s done too. Crazy how a 5ish hour transmission install can get delayed two days with one broken bolt. Spent about 7-8 hours on it yesterday, another 6ish today. It was my first time having to deal with this though, I think it turned out ok at the end of the day.