Broke my Grizzly G0765 7x14 lathe - HELP!

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ARhodes01075

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As the title says, I broke my G0765 7x14 lathe yesterday. I was using a parting tool and it suddenly jammed and STOPPED the lathe. There was some loud clacking somewhere in the internals and I hit the emergency off. It was running at the "slow" speed gear selection on the back of the machine. The lathe WILL work when the gear selector is set to the high speed setting, but not the low speed. At the high speed setting it seems fine. So it looks as if I didn't break bearings or the gearbox frame. There appear to be stripped teeth inside the gearbox. when I turn the spindle by hand in the low speed gear, but not in the high speed gear

I searched the web but could not find a guide on how to strip down the gearing to access the gearbox. The exploded diagram is not detailed enough about what inserts into what, and what gears mesh with what other gears.

I think that the problem is with the combo gear (#24 in the "Main" parts diagram) but I can't tell what it meshes with. I assume that the combo gear and/or the gear it meshes with are damaged, so I should probably replace both. They are not terribly expensive from grizzly (hopefully they have them in stock!)

Does anybody have experience with this repair? Can you point me in a direction to a repair operations manual? What parts am I likely to need?
 
Looking at your parts list, it looks lke you have to remove the side cover, #44 to access the gears. Most likely, both gears #14 and #24 will be damaged. The spindle will have to be pulled to change #14, You should be able to remove the shaft that #24 rides on to change that gear. Most likely, you will have to remove the shift fork as well.
 
Ouch! Looks like you have quite a bit of disassembly ahead of you
Too bad the design didn't include some kind of slip clutch to protect against that type of damage
-Mark
 
RJSakowski said:
Looking at your parts list, it looks lke you have to remove the side cover, #44 to access the gears. Most likely, both gears #14 and #24 will be damaged. The spindle will have to be pulled to change #14, You should be able to remove the shaft that #24 rides on to change that gear. Most likely, you will have to remove the shift fork as well.
Click to expand...

My lathe is post-2015, so, I am using the parts list for the "Model G0765 (Mfd. Since 5/125)"

On this parts list, the "headstock cover" is part # 42. it looks as if I will need to remove all or most of the gears driving the leadscrew. Then the pivot arm (#61) and handle mount (#36). And then the gear mount (#48).

Do I need any special tools like gear pullers or similar? How do I get the shifter fork (#30) off? Does the spindle with all the parts mounted simply slide out of the headstock casting toward the bed? Are the bearings pressed-on?

Once I get the headstock side cover off, does the spindle and the H/L shaft (#26) come out easily?

These are probably all simple and straight forward operations, but it would be wonderful to have step-by-step instructions. Where are the Haynes Manual people when you need them!!??

-Tony
 
markba633csi said:
Ouch! Looks like you have quite a bit of disassembly ahead of you
Too bad the design didn't include some kind of slip clutch to protect against that type of damage
-Mark
Click to expand...
Yeah, I will have to disassemble the whole darn thing! A slip clutch would have been great. Or maybe a weaker drive belt, or a weak key on the motor holding the drive pulley. All these parts are much more accessible, I think. But replacing the drive belt probably requires nearly all the disassembly required to get at the combo gears.
 
I'm sure you will need access to a press. The spindle bearings are probably pressed on, although hopefully not too tightly.
Some of the questions you have will probably yield answers as you begin to pull it apart. Fortunately Grizzly is pretty good about getting spare parts, though you may have to wait a bit for them
Parting off on a small lathe can be difficult/disastrous- I can do small aluminum parts on my 6" Atlas- but never steel. I've stalled it before so I keep the belt on the loose side
 
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Pulling the spindle may require you to come up with some type of threaded rod, nut, and washer arrangement, a common technique on small lathes like Atlas
 
You'll have to pull the head stock and the spindle to change those gears. LMS sells steel replacements, use the steel one on the spindle and buy 2 plastic ones for the jack shaft. When it happens again you won't have to pull the spindle to change the plastic gear, and you'll a spare on hand! I can change mine in 30 min or so.

I have read not to use both steel gears due to the noise and the fact a crash will break the next weakest thing$$$
 
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