1440 Automatic Feed and Threading Not Working

MKSJ, yes the gear is turning. Along with the gearbox input shaft gear. They are all connected so it one turns the other turns. (Sorry, hit the bold button by accident). The position of controls in the picture don't mean much since I have tried various things at various time and moved them all. That was just the last position I had them in for whatever reason. Don't recall what if anything specific I was doing at that point.

Your manual is a lot more informative than the Warco one I downloaded.

The feed selector (H in your manual) does not move into the E or F positions. I suspect that is where the problem lies. But even when it is put into the A or B position nothing happens. IT doesn't feel like a positive detent or I should say it is not consistently a positive detent. I suspect that the bell crank inside is loose on the shaft or something and even if it does go into some semblance of a detent it may not actually be in position. It is hard to figure out how it works from the parts diagram exploded drawings.

Markba, I tried removing the electrical panel but it only goes into a cavity between the headstock and gearbox. The gearbox has some thin metal cover plates to prevent seeing inside. To remove those I have to remove the headstock.
 
So it that is the case, then it is the shifting mechanism in the gearbox. It should be removed w/o removing the headstock, there is usually a series of mounting bolts and dowel pins that would be accessed behind the face plate. There are two removable access plates on the top of the gearbox that can be removed to look at the gear movement. Most likely the issue is either a misalignment of the shifting plates or someone forced the gear selectors and sheared a pin so you are not getting the proper movement. Not a small under taking to dissemble a gearbox like this and get it back together.
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try turning the lead/feed rods when moving the knob into the e/f position.
If the lock knob isn't locked in rock the shafts to lock it.
It is the same as Busybee CT042 which is Jet GH-1440A
 
MKSJ, that diagram shows the plates but it does not show the whole picture. The headstock is bolted on top of the gear box so those plates cannot be removed until one removes the headstock. Indeed, not a small undertaking. I guess I 'll have to get up close and personal and invade its personal circle. O joy!


John O, I'll give that a try but I have my doubts. I can't get the knob to move past the neutral position at all. But its worth a try.
 
You could call Birmingham Machine Tools and speak to technical. You cannot determine how the gearbox is mounted unless you have removed the face plates, the lathes I have had the they were bolted to the headstock, typically they could be removed separately. The front plate of the gearbox/shifter mechanism may come off, but reassembling it may be the bigger issue. You probably answered your own question when you indicated you could not get the gearbox out of neutral.
 
From scoping out said lathe and looking at the manual it appears that the headstock is held to the gearbox with 4 Allen bolts. Two on the chuck end and two at the outer end on the outside. I don't believe there are any bolts passing through the inside form one to the other. If there were then the headstock oil might run down into the gearbox making the former run dry while overfilling the latter. They appear to be tow separate and sealed units.

I agree that removing the face plate would make reassembling it difficult to say the least. I'll ponder the headstock removal task a bit more.

I tried rotating the feed screws with some luck but then the knob stuck in the E position and wouldn't go back into the A side.
 
I did an extensive VFD install on one of these lathes, I am pretty sure that the headstock is not removed to remove the gearbox. The head bolts to the the bed with 4 bolts they are on the outside of the headstock (you can see the two on the chuck side), which is typical of most lathes in this size group. The front electrical panel comes off as well as the cover panel on the chuck side. You should be able to see the gearbox and how it is mounted. The red circles are retaining screws for the side cover and face plates, the blue arrows are the oil site gauges for the headstock and the gearbox, I assume that you have checked there is oil in both.
YCL-1440 Lathe.jpg
 
Here are couple of pix showing what I think are the attachment bolts:



Under the Headstock at the rear. The other one is behind the large gear.
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The gearbox cover plates behind the electrical panel. Mounting screw are marked black with a felt marker.


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Front bolts under the chuck in recesses.

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Before you tear into anything, it would be a good idea to check out one simple item.

In mksj's post #10, the very first photo shows the gear train on the back of the headstock. The small gear at the very bottom is the one that transfers the power into the gearbox. It is retained by a nut on the end of the shaft. Make sure that the shaft is rotating when the gears are rotating. The key that transfers the power from the gear to the shaft may be sheared or missing.

This is kind of a long shot, but worth checking before diving into the gear box.

I know that the Jet BDB and GHB 1340 lathe manuals are available free online. I believe the gearboxes are either the same or very similar to the 1440 lathes. The parts illustrations are very informative.
 
I replaced the bearings in my 13" Jet BDB gear box, it's not that difficult to work on. Just shift everything to the center position before pulling the cover to inspect (drain the oil first).
 
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