5/16'' x 24 Heli Coil - Need to borrow one ...... OR........

[Glennster]

 If any body has a 5/16'' x 24 Heli Coil they could loan me I'd sure appreciate it.  Or, I can buy the actual coils cheap, what I cant figure out is the size to drill and the correct tap to use...... I stripped the stud hole on my new radiator fan clutch....BUMMER!
Any ideas?
THANKS!!!

[cudazappa]

5/16-24 helicoil uses a 21/64" drill.

You need to use the special heli-coil tap.  McMaster.com #91709A153

you know about the coils...  Then there's the tool, which I don't have for that size... sorry.

[GoodysGotaCuda]

have you considered a thread chaser? they are designed to help clean up existing threads.

[Glennster]

There's not much in the way of threads to chase. I ran the stud in a bit crooked, then when I tightened it, it pulled straight and ripped the threads out. That seems like soft aluminum.....

  I think I could get the coil in with a home made tool, the tough part is the correct tap size....

[422STROKER]

Would the insert throw off the balance?  Maybe a new fan clutch is safer?
 
Tom

[Glennster]

 Is balance an issue there?

[422STROKER]

I don't know, but anything rotational out of balance may cause problems I'd think.  Maybe not cause a problem with the motor itself but the water pump?  May be fine too though.  Just throwing it out there though.

Tom

[whitesatinmopar]

  Please excuse my general ignorance here, but is it possible to just tap it to the next size, then merely changing bolt size?

[Glennster]

 If I go to the next size up, them I have to drill the fan to a larger hole size. Not a big deal, but I'd prefer to stick with the same size threads....

[Chryco Psycho]

I think i have a spare kit I could mail out , or you could just buy a kit for $20 or so which about what the shipping would cost there & back

[Glennster]

 THANKS for the help and the offers...... The tap I need is a 10M X 1.0, I've got a buddy that has one!  The cheapest one I could find around here was $38. I bought the coils for $10, I can borrow the rest of the stuff.

[GoodysGotaCuda]

THANKS for the help and the offers...... The tap I need is a 10M X 1.0, I've got a buddy that has one!  The cheapest one I could find around here was $38. I bought the coils for $10, I can borrow the rest of the stuff.

Harbor freight man! you can get a metric tap set for super cheap. It'll do that job. I wouldn't go trying to tap stainless steel or cast with it. Little stuff like that, it's done me well..

[422STROKER]

All that work and there are fan clutches at the parts store for 30 bucks.LOL

Tom

[Glennster]

 I went to O'Reillys, they had the standard for $30 and the HD version for $50.  When I used the HD, I had water temps that were 15 degrees less, that's why I fixed the one I had. But I had to build a collar for the DH, the hole for it was .750'', the hole on the standard was .625''. 

[422STROKER]

I hear you, just bustin 'em a little!LOL

I need a HD on mine, That has the silicone in it right?  I have a small spring on mine and wonder sometimes if it's working properly.

Tom