Einbbx

D21s have T12 bolts? Strange.

No I had the measurements covered, have a little nifty tool that has all metric and standard thread sizes to test bolts. Only issue was my m12 1.25 die had damaged thread and made me think the threading was different. I'm really thankful @Charlie69 the local LKQ yards always have 720s & d21s, but recently they've all been manual.

I assume broken bolt hole will need new thread. What grade is this bolt? Maybe 8?

TAP CONFIRMED it's 12m 1.25. Only two holes need thread, the broken bolt one and another has first half of thread flattened as it dethreaded half the bolt..

I'll try the tap 12 1.25 tap and see how it goes

Thanks for the speedy reply I agree logic dictates it.. but the closest and ONLY die that should work is 12m 1.25 thread. I measured 1.5 and 1.75 thread and it's not even close. But it won't fit the 12mm die with correct thread. Bolt threads are beautiful so it makes absolutely no sense

You may have read my story.. Automatic Z24 ST manufactured date 6/84, Flexplate failed had to replace, during removal flexplate bolt snapped. Now I am trying to re-thread the holes on crank, but have found issue. I have 3 different flex bolt sets Each have different signs on head *Original bolts= upside-down T & 12 *Removed from a manual= MT *Removed from D21?= upside-down T & 13 T12 shortest (tapered end) MT slightly longer (no taper) T13 longer still (tapered) 5 of 6 T12 bolts are UNUSABLE, trying to find suitable substitute. ISSUE Bolt is either 12mm with 1.25 thread or 1/2 with 20 thread. Foreign... should be metric... Used a thread checker and thread looks interchangeable 1/2-20 tap does not fit bolt hole, logic says it's 12mm tap. PROBLEM Bolt seems to fit 12mm-1.25 die but will NOT thread Bolt fits 1/2-20 die loosely but threads nicely. MY CONCLUSIÓN After trying several dies and reading up on my measurements BOLT: Appears to be 12mm, 12 slightly smaller than 1/2 explains loose fit in 1/2 die and tap not fitting in crank. THREAD: Appears to have a standard 20 thread, if it can fit the 12mm die but wont thread with 1.25.. then it must be so? .. is this possible? Is this a real thing?.. or am I crazy!? I need to re-thread but don't want to damage crankshaft, ANY advice is welcomed wholeheartedly Please and thank you all -E.C.V.

Oh snap, m12 no wonder I have the wrong tap kit.. also I believe the part number is 12330 and 12333 for the back and front spacer (in that order)

Is there a part number for those flexplate shims/spacers?

Got it off! Was stuck on hard, broken bolt was clipping it. Now for rethread.. either this bolt hole isn't 1/2 or my threading tool is not 1/2. Slightly aggro about this. Trying to find the right one to rethread this sucker.

Lol ok flexplate.. so how do I pry off that rear spacer, this thing is mucking everything up

My SPLODED flywheel. https://www.instagram.com/p/BM7qAKKgXbgMwIVcf6qF1daWYRD7VNdzwWOvQc0/

It's slow going... this damn thing is some sort of tough I tell you. But it's getting drilled. Could t punch a divot I to it so it's not exactly centered. Never the less I'll continue carefully until I get the whole wide then use something to try and break it apart and remove the chunks. -Thanks all for your input, glad to have your advice

It sounds like a reasonable enough plan to me, I am on PST so I will get on it bright and early and have a whole day to dedicate to slowly and safely drilling out that sum biskit that ruined my whole day. I plan to tap the bolt with a nice punch in the center and working my way on it, with patience and some due diligence Im sure it can be done... given that I have drill bits that can handle the bolt. It was a bit of a nightmare... but I figure I can always do the whole works later on if need be, but for now I just want to get her on the road and enjoy her a bit. I don't think I'll be posting pictured then.. maybe I'll find a way someday, I can't even upload a profile pic because the demensions are so small! Well I learned a thing today about titles, thanks for being a good help and a good sport wayno.

Unfortunately I am unable to post pics, possibly due to the fact that I'm a newer member to this place? Or perhaps I just don't know how to find the option. But the answer is the bolt broke flush. I was not aware that the engine/crank side had a plate on it aswell, I will remove it and see what I can do. Thanks for the suggestion I will likely go through the process of drilling it out as described by Datsunaholic, and yes it is a z series. Z24, I went to junkyard and tore apart a clutch kit and Flexplate to see what I was dealing with. Major differences is that manuals have a thicker flex (cast iron) and the one on mine was far lighter material. I do own a tap and can rethread the hole. I will likely replace the spacer with a fresh one. I'm so glad you guys are here to help me out, my heart sunk when that bolt snapped... that's also why it's in three threads hahaha I panicked and was desperate for advice! Thanks so much. I'll let you guys know how it goes (since this is apparently a rare occasion of breaking a Flexplate bolt haha) -and please keep the good advice and encouraging info coming. I'll take all I can get in this endeavor