Joined: Oct 31, 2010 Posts: 13 Location: Cleveland, OH
Posted: Mon Dec 11, 2017 7:38 am Post subject: Autolite 2245 thread size?
Looked through ORD 9 SNL G758 for the Autolite 2245 spark plug thread size on the plug wire end, but only found the info below. I mucked up a couple threads and would like to clean them up.
One must be carefull not to use standard metric taps on spark plug to cylinger threads. The actual 14mm plug thread is considerably smaller than the nominal 14mmx1.25 standard fine thread.
The easiest clue to the top end thread size of the plug is the parts manual ORD 9 SNL G-758 where you were already but just look at the page for the plug leads, page 151, last item on the page.
You can get a die for 14mm spark plugs at many auto parts stores.The threads on the top of the plug are 5/8x24.14mm spark plug dies are common as are the taps.
1-Spark plug lower threads are not nominal they are slightly smaller then nominal and require a spark plug thread size IE 12mm, 14mm, 18mm specific tap or die. An example is the nominal 14mm-1.25 tap will cut a thread that will fit the plug loosely. The special spark plug 14-1.25 and the correct drill size for it will leave a tapped hole that fits the plug tightly.
2-The upper barrel thread size is 5/8-24NEF-3 however the M38A1 ORD 9 shows 11/16-24NEF-3 which is too big. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Yes. I never tighten those spark plug shield nuts more than wrist snug. Overtorquing will crush the end of the barrel and damage the nut threads on the next removal.
On the loose issue note: I am quoting the M38A1 parts manual thread size which reads 11/16-24NEF-3 for the nut PN 7528187.
The M38 ORD 9 lists the 7528187 nut thread size as 5/8-24NF-3.
So the next step is to try the 5/8-24NF die for fit. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum