Greenie headstock reassembly - single remaining set screw

[john_001]

Jacob Anderson's headstock teardown video, part 3 https://www.youtube.com/watch?v=JzbgSSpaXzs shows him loosening a set screw under the idler shaft (starting around 1:25) that I can't find on the parts diagram. It's hidden under the eccentric bushing. It looks like a 3/32. Any chance that could be it?

[edma194]

That would be the version that has a groove in the bearing. You will need that screw.

[JPG]

I do not recall it being a 10-24. IIRC it is a 5/16-18 cone point with 5/32 hex socket.

My goldie parts list says: 5/16-18 x 1/4 set screw Part # 1028

[chapmanruss]

John_001,

You said

Jacob Anderson's headstock teardown video, part 3 (link removed) shows him loosening a set screw under the idler shaft (starting around 1:25) that I can't find on the parts diagram. It's hidden under the eccentric bushing. It looks like a 3/32. Any chance that could be it?

The set screw he removed is the one in the Eccentric to lock it to the Idler Shaft Bearing. On Mark 5's made before 1964 when the part number changed that is part P 1028 that JPG refers to. It is a 5/16" - 18 x 1/4" set screw but I do not know which end it may have had through the years. None of the several parts list I have looked at give the type of end that set screw has, be it cone, half dog (unlikely), cup or other. After the number change in 1964 it was part number 139367. On the first Mark 5's made prior to 7-54 they do not have that set screw in the Eccentric. Adding that set screw and the Bearing Retainers (part number A 3274) were two of the first changes made to the Mark 5 after its introduction. This was to keep the Idler Shaft Bearing and Eccentric from moving in the Headstock Casting's mounting hole.

[HopefulSSer]

John_001,

You said

Jacob Anderson's headstock teardown video, part 3 (link removed) shows him loosening a set screw under the idler shaft (starting around 1:25) that I can't find on the parts diagram. It's hidden under the eccentric bushing. It looks like a 3/32. Any chance that could be it?

The set screw he removed is the one in the Eccentric to lock it to the Idler Shaft Bearing. On Mark 5's made before 1964 when the part number changed that is part P 1028 that JPG refers to. It is a 5/16" - 18 x 1/4" set screw but I do not know which end it may have had through the years.

That screw in my 1960 Greenie has a cone end.