Craftex CT089 Lathe Gear Shifting Problem

[SteelFred]

Hello Everyone,
I've had a Craftex CT089 13"x24" lathe from Busy Bee for almost 10 yrs and it's worked fairly well. Lately I've noticed the left gear change lever needs some jiggling to get it to move, and yesterday it is stuck. I've never shifted the levers while the lathe was running, and have been gentle with it over the years. I removed the top gearbox cover and unfortunately it's not possible to see what the problem is. I can see the right gear shift lever working properly but the left one is behind some large gears (and oil). I can still use the lathe but only have two speeds now.
Anybody have any experience with this or have an idea what might be wrong? I dread thinking about disassembling the whole gear box but am prepared to do that if necessary.
Thanks in advance for any insight.

 

[Dusty]

Hi there, for starters I would loosen the set screw and remove the handle on the shaft. You may find that the set screw slipped some or the handle simply requires adjustment. Perhaps you've already checked that. Craftex CT089 manual doesn't offer much in the way of problem chasing. Bill

 

[SteelFred]

Hi there, for starters I would loosen the set screw and remove the handle on the shaft. You may find that the set screw slipped some or the handle simply requires adjustment. Perhaps you've already checked that. Craftex CT089 manual doesn't offer much in the way of problem chasing. Bill

I looked at that- it's actually a pin that goes right through the handle and the shaft. The problem is something is stuck inside the gearbox, maybe a burr on a gear that prevents meshing? There's about 1/16" movement then a hard stop. This lever slides a gear sideways on a splined shaft to engage one of three other gears. Right now it's stuck in the far right position.

 

[RobinHood]

Welcome SteelFred. Once you post a few more times, you’ll be able to upload pictures.

Maybe the shift pin /shift fork has come partially out of the gears’ groove. If it is submerged in the oil, probably best to drain it to get a good view of what might be happening, and take some pictures.

Edit: never mind the extra posts - you can already post pictures: just saw your intro.

 

[SteelFred]

Thanks RobinHood, looks like I'll need to do that. I'll post some pictures as soon as possible, thanks.

 

[Janger]

If you wiggle the chuck and or the power feed / threading shafts while wiggling the knob does it move?

 

[SteelFred]

If you wiggle the chuck and or the power feed / threading shafts while wiggling the knob does it move?

Yes I've wiggled the chuck back and forth in both settings for the right gear shift lever but no change. Previously I remember the left gear shift lever would only move when the right gear shift lever was in one position only; I wonder if something got loose although I'd hate to think there are any screws holding things together in there.
I just ran the power feed as well in both settings and there is still no movement on the left gear change lever.
I don't know how many of these CT089 lathes were sold but I notice there is no mention in any Youtube videos. Maybe I'll be doing the first gearbox takedown video lol!

 

[RobinHood]

I wonder if the spring loaded ball detent is worn and the ball is jamming the shift lever shaft?


The diagram is not detailed enough to see how the shift fork is attached to the shaft. Could be another place to look in case the fork has lost the indexing to the shaft causing it to jam.

 

[SteelFred]

This morning I took apart the left gear shift mechanism. The spring ball bearing appears OK as the depression the ball goes into is quite shallow. I put the tapered retaining pin into the shift fork and it's still stuck as before so the problem is down there in the oil. I'll drain it later today but I think I'll also have to remove the headstock spindle- will there be any alignment issues if this is removed or will it self-center on re-assembly?
Here are some pictures of the progress so far:
The Left Gear Shift Lever Disassembly shows the parts, there is a tapered pin which comes out only one way, a spring, ball, gasket, bushing, and the shift fork. Everything passed out the front of the gearbox without any trouble.
The Internal Gearbox Closeup shows how difficult it is to see what is going on as there is the headstock shaft and another large diameter shaft obstructing the view. These will have to be removed although I'll try shifting the gears manually after the oil is drained.
The External Gearbox shows the headstock shaft bushing held by 3 screws. I'm wondering how safe this is to remove and re-install so the alignment doesn't change.