Bolt and thread size

[Gregorypaul]

Hello everyone,
I am having a crankshaft balanced for a engine rebuild at a machine shop for a 1994 4.0 jeep wrangler with a manual transmission. I told my machinist I would drop him off a flywheel,vibration dampener and hardware. Having a hard time finding information on bolt sizes. I know everything has to be grade 8 and the flywheel bolts have to be for that purpose but what are the thread sizes and lengths? Just checked my factory service manual and just gives torques, been checking online but cannot find what I need for sure.
If anyone here knows and would share that would be helpful.
Thanks in advance, Greg.

 

[superj]

I have no idea

 

[LGR]

what is wrong with the bolts already in those spots?

 

[Gregorypaul]

Hello LGR,
Building on a different core motor that I am currently running. Turning 275,000 miles and building it's replacement.
Thanks, Greg.

 

[Gennybro]

The machinest should be able to supply that information for you,unless they are a cnc machinest. "their abilities are limited". What you need to do is measure the inside of the threaded hole useing a dial caliper. The measurement you get will be the tap drill size for that threaded hole. Now you need a tap drill size chart to tell you what bolt thread uses that tap drill size. Now that is going to narrow down your search to the correct bolt size from one to possibly two bolts that use that tap drill. For example,a 1/4-20 thread uses a #7 tap drill, a 14-24 NS thread uses the same tap drill. If you run into that situation"which I doubt that you well", purchase the 2 bolts and see which one fits, be careful when doing this make sure your threaded hole is clean and the bolt threads in easily,you dont want to use the wrong bolt and cross thread it. The length, your just gonna have to do some measureing on the items that your bolting togeather.

 

[Gennybro]

I have the tap drill chart,furnish me with the I.D. measurement and I will give ya the size ya need.

 

[Gregorypaul]

Thank you Gennybro!