Alternator Bolt

Posted By: ct440rod

Alternator Bolt - 05/21/18 03:30 PM

Anybody know thread size/pitch for bolt that holds alternator for 70 challenger .. the short one that threads into alternator.
mine is stripped and trying to find heli coil.
thanks
Rod

Posted By: Blown_Hemi

Re: Alternator Bolt - 05/21/18 03:35 PM

Should be 3/8" x 16.

Posted By: ct440rod

Re: Alternator Bolt - 05/21/18 04:03 PM

The long one that goes into block is 3/8. The one that goes into alternator is more like 5/16 but a 5/16 fine or course nut does not thread on it. Hard to believe it was metric in 70 . .

Posted By: moparx

Re: Alternator Bolt - 05/21/18 04:27 PM

Originally Posted By ct440rod

The long one that goes into block is 3/8. The one that goes into alternator is more like 5/16 but a 5/16 fine or course nut does not thread on it. Hard to believe it was metric in 70 . .

no metric threads used in 1970. possibly, over time, someone stripped or tore out, the original threads and re-tapped to metric in order to save the alternator. if you absolutely need to save it, drill and tap the offending hole for a helicoil.

Posted By: buildanother

Re: Alternator Bolt - 05/21/18 04:35 PM

Supposed to be 5/16" coarse.

Posted By: moparx

Re: Alternator Bolt - 05/22/18 03:56 PM

Originally Posted By buildanother

Supposed to be 5/16" coarse.

yes. 5/16-18 thread.