[morzh]

Gosh. I always re-discovered how to do it, took me 2-3 minutes every time.
Now that I think of it, the c-clip is there but has nothing to do with taking this apart.
I think you just push that sprocket agaisnt a piece of wood, and it just comes out. You have to push the shaft (the tuning end where the knob goes on) in a bit before pushing the sprocket.
I hope so.

I also found this

https://philcoradio.com/repairbench/tips/svctip39.htm

[HowardWoodard]

Oh... That link is gold man! Thank you so much.

I'll see if I can get this thing fixed and will post the results on this thread.

[462ron]

Hi Howard, if memory serves, and many times it doesn’t, I vaguely remember working on a Philco that had that pin you have circled in yellow with a question mark. I believe I used a magnet to extract that pin to disassemble that mechanism!

Ron

[HowardWoodard]

Thanks 462ron. I have it soaking right now but will test the power of my shop light magnet on the pin when it comes out.

[morzh]

The gear on the 37-604 is exact same, but there was no pin.
The pin exists on the gear of 37-116 or those ones with robo-dial from this and the next year. But those are different gears.
As I remember, the technique was nocking the pin out. I forgot how I got it out.
I am sure a Philco doc should exist on thie gear, same as it does for the 37-116 robodial. Which BTW does have the technique for getting the pin out, and we do have that doc in our library somewhere.

[HowardWoodard]

Well, the paint thinner didn't get the job done but some heat did.  I got it apart, got everything cleaned up, re-lubed, and then back together.  As I was putting the retaining pin back in, the vernier shaft popped out.  The ball at the end of the shaft that, along with the three bearings that sit down behind it and holds the shaft in, had separated.  I thought that it had broken off but on closer examination it appears that it is a completely separate piece.

Before I start trying to source a vernier tuning shaft I want to see if I can understand how it was manufactured in the first place.  Maybe I can fix it.

When I first looked at the shaft, I assumed that it had been machined out of one piece of metal, but it isn't.  The small metal ball shape at the end, used to retain the vernier shaft inside the course shaft, is a completely separate piece and is attached to the end of the shaft, either with solder or glue of some sort.  You'll note in the picture that the ball is perfectly round and, under microscope, shows a faint color outline that matches the rim on the vernier shaft.  The end of the shaft is hollow.  The ball does not sit down inside but rests on the lip around the top.  I don't see anything on the ball that looks like pieces of the shaft or residue of any sort.  That's part of why I think it might have been soldered.  I had to heat the unit quite a bit to break the coarse shaft loose and maybe I got it hot enough to melt solder, which would account for the clean separation of the ball and vernier shaft.  Anyway, as you can probably tell, really, I don't have a clue.

Do any of you know how its attached and have you ever heard of anyone successfully repairing it?

Thanks in advance...
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[morzh]

I think you have all pieces in place, none broken. Get the gunk out, lube and re-assemble. It should click in place.
I think (I never dealt with this very one, only with similar ones), the round-cap-ended pin goes into the spring, and the ball goes between the shaft and this pin's cap.
The three balls in my shaft go into holes on the side and are propped up to the sides with the shaft that presses on them; this is a bit different, but the idea is, the balls are between the walls of the cylinder and the shaft and serve as a ball bearing, so there has to be some groove they go into.
The small ball and the spring keep the shaft taut. Usually, when assembled, the shaft is pushed in and clicks in place.

I do not know how this interacts with the pin; mine did not have it.
Also, see if you might find (Google it up) the info, Google your radio model and "tuning shaft assembly"; I am sure you are not the first person to deal with it. If not here than on ARF someone had to.

[MrFixr55]

I'm gonna hazard a guess here. the ball was likely glued or soldered to the shaft.

The pin that looks like a nail goes into the spring. The spring goes into the "outer" brass shaft.

Put the inner shaft into the outer shaft and hold the 3 balls in place Push the inner shaft into the outer shaft only to the point where the balls seat the farthest into their holes. Insert the assembly into the steel "collar. When you let go of the shaft, the spring will push the shaft out, so the 3 balls contact the ball soldered in place, keeping the shaft in place. The ball bearings act as a planetary gearset.

[HowardWoodard]

Thanks. I'll see what I can find about soldering or gluing things to a steel ball bearing.

[morzh]

I am not sure you need to glue it. You just need to assure the ball stays im place when you insert this; this could be done using thick (calcium-based) lube at the tip.

[HowardWoodard]

Hi morzh.  I apologize for being so dense, but I clearly must not be understanding what you are saying because when I try what I think you are saying, the fine-tuning shaft will not stay in.  In the included picture I'm showing you what I think you said I should do.  Please let me know where I'm misinterpreting you.

   

[morzh]

Yes the three ball bearings should go in the holes.
The spring with teh cap should go first, then the balls (with some lube to hold them).
Then the fine adj shaft with the small ball.
Then the whole thing (both shafts, one inside the other) should go inside the larger cylinder, with the fine shaft inserted such that balls are not interfering with the whole thing going in.
The whole thing should be pushed in untill some sort of latching happens while it is being pushed in.
I am not sure what's inside.
The big cylinder should keep the balls inside so they do not let the fine shaft get out.

I never disassembled this, so I am kinda modelling it in my head, based on similar gears (which are not 100% the same).

[HowardWoodard]

Btw, the thread you provided me (https://philcoradio.com/repairbench/tips/svctip39.htm) with the service hint & tip on refurbishing this tuning shaft was written by "Tom Burke" in 2004.  I don't find a Tom Burke listed as a user her on this site.  Perhaps he was an employee of Westridge Consulting who copyrighted the article.

He's the guy who used his own lath to refinish what he called the "end-ball".  It would be nice to be able to ask him if that ball came apart from the shaft.  It reads like it did not.

[morzh]

In my shafts (yes they are a bit differnt but the idea is the same, three balls as planetary gear and a small ball and a spring at the end) that small ball was separate. Even if it was glued (doubt it), it would be just to hold it to make the insertion easy. No functional change because of it.

[morzh]

auto-tuning.pdf Size: 3.12 MB  Downloads: 18

See if this helps. This is Philco Auto Tuning service bulletin. I think this is same as yours. I used it on my 37-116 and 378-690.