Slave Cylinder Cross-Threaded

[DunkThemMuffins]

Howdy,
Wasn't exactly sure where to post this on the forum; I hope this section is appropriate.

The threads on the bellhousing for my slave cylinder are cross-threaded... I know they need to be tapped, but I'm not entirely sure what size to use, or if it's ok to tap them without dropping the gearbox to clean out any shavings. I would really appreciate any advice. My BRZ has been down for a little over a month for a DIY clutch job and gofast parts, and I was RIGHT about to finish today, but then this occured.

Thanks!

[Capt Spaulding]

I can't address the drilling issue. I don't know if the mounting holes for the SC are blind or thru. But, if it were me, i wouldn't just drill and tap it. I'd much rather install an insert. For a long time I used helicoils and they worked well enough. Eventually, I discovered "TimeSert" repair kits and can't bring myself to use anything else. It's not the case here, but if I have a bolt going into aluminum that will be removed and refitted regularly, I have been known to drill out the good threads and install a timesert just for the peace of mind of not worrying about stripping the hole.. A word of caution however, they are not cheap by any means.

[DunkThemMuffins]

Originally Posted by Capt Spaulding

I can't address the drilling issue. I don't know if the mounting holes for the SC are blind or thru. But, if it were me, i wouldn't just drill and tap it. I'd much rather install an insert. For a long time I used helicoils and they worked well enough. Eventually, I discovered "TimeSert" repair kits and can't bring myself to use anything else. It's not the case here, but if I have a bolt going into aluminum that will be removed and refitted regularly, I have been known to drill out the good threads and install a timesert just for the peace of mind of not worrying about stripping the hole.. A word of caution however, they are not cheap by any means.

Looking into those now that you pointed them out. They look really useful! Never thought of those. I'm not sure what the pitch/diameter is for the SC though, I thought they were either M8x1.25 or M10x1.25. Ran out of daylight today so I figured it'd be something for my next day off.

[Capt Spaulding]

I took a quick look at mine and the bolt heads are 14mm. Assuming they are JIS that would indicate a 10x1.25. BUT: don't trust my assumptions - confirm the size before you buy anything.

[DunkThemMuffins]

Originally Posted by Capt Spaulding

I took a quick look at mine and the bolt heads are 14mm. Assuming they are JIS that would indicate a 10x1.25. BUT: don't trust my assumptions - confirm the size before you buy anything.

Measured them today before work, they are M10x1.25. Just like the bellhousing-engine fasteners lol. Thank you bro, you've given me some useful info. Can't wait to drill some holes!

[DunkThemMuffins]

Originally Posted by Capt Spaulding

I took a quick look at mine and the bolt heads are 14mm. Assuming they are JIS that would indicate a 10x1.25. BUT: don't trust my assumptions - confirm the size before you buy anything.

Update: Out with the old threads, in with the NEEEW threads! I didn't have penetrating oil handy so I did something stupid and just used a lot of high-temp grease to catch the metal shavings and lubricate.



Came out really nice, and the threads are perfect. Thank you for the advice and info!