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South Bend 13" Lathe Bearing Issues

Greenlee52

Aluminum
Joined
Apr 7, 2020
Location
Theodore, AL, USA
I hope I make sense on this. I bought this lathe 2 years ago off eBay. The young man who bought it didn't have it long before he decided to sell it. He is not a machinist and didn't know the lathe had some serious issues. After getting it home it took me awhile to get it all unpacked. I am disabled so there are weeks I am unable to do anything and that's why it's taken so long to discover what's going on. I was building a custom aluminum come to house a GPS device for a small helicopter. I was given a print and a shape, so far so good. When I was running on high speed (3 step pulley) the lathe locked up. I reached over to cut the power and it started running again for a few seconds and locked up again. I thought it was the motor (3 HP, 3 Phase). I let it cool and ran it on the slowest speed, it ran fine. Back to high and it locked up again. As I was leaning down I had my hand on the rear bearing cap and it was HOT. The oil git cups always showed full. I decided to remove the caps and take a look at the bearings. I knew the sequence from reading Keep Your Lathe in Trim (?) as to not damage anything. The shims were in bad shape, rear front had a shim thickness of .003 or .004 and the back side was around .011, seemed off to me. The front outside was .009 and the back side was .013. The spring loaded capillary oilers were broke in half so no oil was getting to the bearing, I don't know how it ran in the first place with what little it had on the journal. The back journal showed damaged but you really couldn't feel it with your finger nail. The rear oiler tube was pushed down flush and turned 90* facing forward, no hole to put a wire through to hold the new capillary oilers down when installing the spindle. I bought a set of laminated shims and latheman2 was kind enough to tell me that the starting point from the factory was 0.018. Shims came in today. One other unusual feature was the 3 expander shims cut out the same size as the top of the expander on the larger front bearing. I'm going to pull the bull gear off and see how the expander fits inside of the bearing cap, Ted, latheman2 said he saw no reason for the shims to be there. I'll add some pictures after I find out how to load them to the post. I don't have a clue what to test the spindle with. Can I use any kind of indicator or does it have to be a test indicator? I don't have much in measurement tools at the moment. Any suggestions are appreciated.
 
Be it any kind of engine, transmission, gear box or whatever, Moving parts need oil clearance. On this type of thing I'm looking for .001" to .0015". That's me personally, others may vary. But I want to see that on an up and down check on each bearing journal, as well as side thrust, moving the whole spindle back and forth.

You may go a little tighter or looser than .001"-.0015", but keep in mind there is no oil pump, no oil pressure to force oil, so I err toward loose vs being tight. As you do checks, adjust shims, oil and roll spindle by hand. Ask yourself if its dragging or spinning nice.

A magnet base dial indicator set up can check all that. Handy for getting work at zero too. Nothing too fancy, a .001 increment indicator, with a travel of a 1/2" or 1".

Place indicator pointer at 12 oclock on chuck/spindle. Get a prybar and apply pressure at 6 oclock somewhere, not your whole body weight, but put maybe 50-75 lbs into it. Get your reading. Do to both bearing caps.

Then set thrust. Stick pointer of dial indicator straight at face of chuck/spindle. Use prybar or screw driver to nudge spindle back and forth.
 
Yes Sir, I removed the pipe plugs and found them. The rear tube was flush because someone put it in facing the wrong direction. They were trying to align the hole with the oil return passage front and rear where the oil goes back to the base of the oil capillary. It was still a long ways from lining up so they left it flush. I bought new tubes from Latheman2, I was glad he had a set. He also told me I would have to drill new holes after they are installed. I just hope with my lack of experience that I can get the right numbers back on the spindle test. I'm going to get my neighbor to do the heavy work so I can read the dial. I was amazed it ran in the condition it was in. Very poor work done by the old machinist who owned it and he's 900 miles away. I would gain nothing by confronting him about it, I'm old enough but he's way older than me. I'll just fix it and be happy it's running again. Appreciate your advice. There's a lot to learn from this forum.
 
I thought I replied to your thread, maybe not. A lot of good information you put out. The shims with my lathe were way off. I was reading the booklet on Keeping your lathe in trim and it stated there should be only .001 difference between the inside and outside of the front or the back bearing. I spoke with Latheman2 about shims, he stated from the factory with laminated shims that the thickness was 0.018. Prior to removing the bearing caps you could hardly turn the spindle, with the 8" 4-Jaw Chuck I used the chuck key to help turn it. Maybe all of that will change and I can follow your instructions which are really good. I thought a lathe spindle would turn easy with no load on it. Not mine. I don't understand the 3 additional shims made to fit the top front expander. I saw one article in PM from 2008 where a member suggested using shims to keep the expander from pulling up so hard. I was told that the bearing caps are not interchangeable and fitted from the factory specific to each lathe built. It makes me wonder if the bearing caps are original or not. If everything was going great and you pulled the spindle out to check the capillary oilers why would anyone modify and make such dramatic changes in shims and adding expander shims?? This is why I'm at a loss and asking questions. I know they don't make sense but these are some big differences from how the factory set this lathe up. I guess it happens to the first time buyers more than the pros that know what to look for. I'm trying to learn so I don't make this mistake again. I appreciate your input and suggestions, thanks
 
I need to add this, I understand now after reading a response from several PM members the difference between a tool room lathe and a engine lathe. Thanks for explaining this. I tried to add some pictures but my PC did an update which is automatic. Everything is gone, documents, pictures, videos, etc.. I added some more pictures and the next morning it's the same thing. I see where there are a lot of folks with the same issue going on, I have to put this with a IT friend who can fix it and then I'll get the photos of the shims and bearing caps.
Maybe someone already knows and can tell me is the bearing caps were all milled to the same depth for the expander to sit in? Is it possible to carefully file the ridges where the expander pulled too hard against the bearing pulling the brass up slightly at the bevel points of the expander side where the small piece of felt sits. Thanks
 
South Bend 13" rear bearing issues

Remember these are industrial tools they were likely used hard. An repaired by whoever was willing to try, then replaced by another machine.

First off let me say thanks for all the good advice. Yes this lathe has seen some hard days running. It was used at a place in Indiana called Calumet Castings. I don't have any additional information to explain why the bearing cap on the rear is out of specs like it is. I didn't want to say how many times I have tried to set the rear bearing, let's say between 50 to 100 times with the same results. The front bearing is perfect, it has a clearance of .001 and remains cool at all speeds. Here's what changed, I have 3 bearings to play with and a great used spindle that came out of a running SB lathe that was updated to a D1-4 spindle. With the old spindle I could not spin the chuck without the chuck handle in the chuck. It never would spin by hand. I had to get out of the box and look at this with a different point of view. I shimmed it back to how it was when I bought it. Rear inboard shim thickness was .028 and Rear outboard thickness was .014. It ran almost 1 minute before trying to lockup. I removed .002 from the inside and it ran almost 3 minutes before getting too hot. My bearing caps are original so what did the old machinist know and why did the shim difference of .014 from side to side work when nothing else would? Now this lathe only ran at the lowest speed but when I went to polish an item in the chuck it locked up fast. That's when I tore it apart and started seeing what I had. My lathe will not run when it's set to the correct settings according to South Bend. It would be nice if some experts lived near by and wanted a real challenge to show me how to set the bearing up. I've been looking at the headstock and bearing cap. From the measurements it's out of round. The mating surface on the outboard headstock where the alignment pin and Allen head cap screw secure the bearing cap looks like it was pulled up at the threads. I'm still 1/16" inch high at the small breather hole. The rear Allen head cap screw was stripped so I tapped all the cap screw holes in the headstock using a bottom tap and adding new Allen head screws 1-3/4" in length over the 1-1/2" length that came from the factory. I have limited resources in tools so I use what I have and hope I don't make it any worse. I was going to take it Abom79 since he is about an hour away but he never responded to my emails. Probably good he didn't, I have spent too much on this lathe already and I'm sure his rates are higher than I can afford. If anyone has experienced a situation like this one could you please let me know and how you found the issues and what it took to correct it. I'm not in good shape and to be completely honest I don't want to leave this with my wife in case something happened to me. At least if it runs it will sell. Thanks for looking
 
I have old tired eyes, if you could add paragraphs with spaces, i would appreciate :D.

I see you say you have .001" on front bearing. I don't see a reading for rear bearing. I need that, and you do too.

I do see you said you locked up, then removed shims. Locked up again. You may have forgotten to add details that I don't know. But removing shims will make it tighter still. If anything, you need to add shims.

I prefer an even number of shims on both sides of the cap, or close to even. Does not need to be exact, but prefer to keep it close.

If you go back to post #2 of the thread, I mentioned putting a dial indicator on head stock caps, or there-bouts and indicate off spindle. Do that, front and rear. You want .001-.0015" on both sides of spindle. Use a pry bar, very big screw driver, anything. . . but lift up and down on spindle to get a reading on both sides.

Lastly, get a thrust reading. That's back and forth,with spindle moving toward and away from tail stock. This can be tighter at .0005", but at .0005" to .0015 you should spin without issue.
 
Pull the rear cap and plop a piece of plastigage across the shaft. Tighten the cap then open it up to see what the plastigage says. There's your starting point. Then shim up/down as needed and check it again.
 
Before I start adding more detail could someone explain to me how to reply with a quote? Just a segment of a post that helps get a point across. Thanks

Maybe replying from a phone is the same, not sure, but if you do phone app to "desktop version", or just use a pc, then click "reply with quote":

63.jpg

When the area comes up you type in, the quote is there. just click so cursor is there. Back space any info of quote you dont want.
 
Maybe replying from a phone is the same, not sure, but if you do phone app to "desktop version", or just use a pc, then click "reply with quote":

View attachment 319265

When the area comes up you type in, the quote is there. just click so cursor is there. Back space any info of quote you dont want.

I appreciate the instructions, other forums I have used with the multiquote option you highlighted the quote and it automatically did what you wanted. This is a little different but workable so again, thanks
 
I have old tired eyes, if you could add paragraphs with spaces, i would appreciate :D.

I see you say you have .001" on front bearing. I don't see a reading for rear bearing. I need that, and you do too.

Yes sir I can do that and make it easier to read, but I have old tired eyes too and would appreciate a

larger picture of your assistant working on your lathe. lol

I did have numbers for the rear but didn't list them. I have removed the spindle once again to check the

headstock and bearing cap. I set it up like a clock measuring 1 to 7 and 10 to 4 on each end, front and

back. I'm showing several thousands difference from the rear to the front. I'm going out to the garage to

get my notes and will post the numbers in another post this afternoon. My thoughts are that the oil between

the bearing and the shaft is not even or parallel across the surface. If that makes sense
 
I'm going to ask some questions here in no particular order:

1) to your knowledge, has anyone installed ANY of the bearings shells by crushing the top of them with the bearing expanders? Tip off here is you see an expander-shaped dent in the top of the shell.

2) are all the expanders installed correctly and have the small screws snugged up before running the lathe? If the expanders are installed correctly you would have to disassemble the bull gear and cone pulley off to remove them. They should be locked on the bearing when installed correctly.

3) have you drained and flushed the oil reservoirs?

4) are you aware of the correct way to check bearing clearance?

5) if all looks good I can only suggest you install enough shims so that you have excess clearance, possibly 0.003 inch clearance on both bearings or so, and run the machine. Keep the thrust adjustment quite slack as well. If the rear bearing still heats in operation at speed I suggest there is another problem not yet identified. If it runs OK then reduce the clearances by one or one-half thousandth, and repeat.

My go-to oil on these spindles is 0W20 mobil one synthetic engine oil. I have had 10 inch SB machines heat the spindles, when they were adjusted to factor spec, and run on the highest spindle speed, using the correct spindle oil. After flushing and re-filling with synthetic engine oil that problem stopped for me. This happened in two separate heavy 10s that I owned.
 
I have old tired eyes, if you could add paragraphs with spaces, i would appreciate :D.

I see you say you have .001" on front bearing. I don't see a reading for rear bearing. I need that, and you do too.

I do see you said you locked up, then removed shims. Locked up again. You may have forgotten to add details that I don't know. But removing shims will make it tighter still. If anything, you need to add shims.

I prefer an even number of shims on both sides of the cap, or close to even. Does not need to be exact, but prefer to keep it close.

If you go back to post #2 of the thread, I mentioned putting a dial indicator on head stock caps, or there-bouts and indicate off spindle. Do that, front and rear. You want .001-.0015" on both sides of spindle. Use a pry bar, very big screw driver, anything. . . but lift up and down on spindle to get a reading on both sides.

Lastly, get a thrust reading. That's back and forth,with spindle moving toward and away from tail stock. This can be tighter at .0005", but at .0005" to .0015 you should spin without issue.

I'm going to ask some questions here in no particular order:

1) to your knowledge, has anyone installed ANY of the bearings shells by crushing the top of them with the bearing expanders? Tip off here is you see an expander-shaped dent in the top of the shell.

2) are all the expanders installed correctly and have the small screws snugged up before running the lathe? If the expanders are installed correctly you would have to disassemble the bull gear and cone pulley off to remove them. They should be locked on the bearing when installed correctly.

3) have you drained and flushed the oil reservoirs?

4) are you aware of the correct way to check bearing clearance?

5) if all looks good I can only suggest you install enough shims so that you have excess clearance, possibly 0.003 inch clearance on both bearings or so, and run the machine. Keep the thrust adjustment quite slack as well. If the rear bearing still heats in operation at speed I suggest there is another problem not yet identified. If it runs OK then reduce the clearances by one or one-half thousandth, and repeat.

My go-to oil on these spindles is 0W20 mobil one synthetic engine oil. I have had 10 inch SB machines heat the spindles, when they were adjusted to factor spec, and run on the highest spindle speed, using the correct spindle oil. After flushing and re-filling with synthetic engine oil that problem stopped for me. This happened in two separate heavy 10s that I owned.

I spent 45 minutes writing a reply last night and one little computer glitch and it's gone so I'll add it

again with the short version. Measuring the headstock and bearing cap was a total waste of time. It's not

round for a reason, The bearing thickness and average starting point for shims has to be considered before

line boring. Both ends, rear small bearing and front large bearing are on separate planes or levels because

of journal size and bearing size. I understand completely the procedure for setting clearance for the

bearings to run properly. I currently have 3 bearings in great condition and 2 extra expanders, one I

flattened the VEE by 1/32" to improve oiling as suggested in the 4 page manual that covers bearing

adjustments. I shortened to felt 1/8" to see if it would help but it didn't. After losing what I wrote last

night I went back to the garage and put the spindle back in. The front is set to .018 on each side and the

clearance is just under .002, prior I had it set to inboard .017 and outboard .018 and it was almost a

perfect .001. I'm not worried about it because it consistently runs


the way it should. I set the rear bearing at .021 on each side and after doing the lift test I have .008

clearance. The thing is it won't run without getting hot within 30 seconds. The longest period it ran was

when I set it close to what it was originally and that was .028 inboard and .014 outboard. The last time the

spindle was in the headstock I removed .002 from the inboard side and .001 from the outboard side because it

already had .014 difference from side to side and .001 is what's suggested.

I mentioned this for Texas Gunsmith, he had asked in a earlier post.

My problem is the lack of lubrication evenly across the journal surface, I'm not positive but this appears

to be the issue I am having. I have removed shims from the rear bearing until I get to .002 but it will

barely turn or not turn at all. When it gets hot it pours out smoke so you can smell the oil burning. I

using Mobile1 synthetic 0W-20 hoping this would help but again nothing has changed. I have backed off on the

locknut with no positive results. I know my settings are correct but something else is going on and that's

what I am trying to explain.

I haven't taken any measurements side to side but I intend to do that today.

I have brand new capillary oilers, I have flushed out the reservoirs and cleaned the breather holes out with

pipe cleaners.

Maybe there is no way to correct this problem since it's difficult to see. I thought about shimming up the

bronze bearing just to see if it would make a difference. The instructions are clear enough for anyone to

read but apparently the rear bearings on the 13s and other size South Bend Lathes have an issue with heating

up but it doesn't apply to all of them. I bet all these lathes ran like champs from the factory because they

had all the special tools to put them on the money but the first time you take them apart you are taking a

chance that it will go back together the way it came apart. I'm amazed to see a 13" on YouTube and the guy

puts his hand on the chuck and it spins like it has ball bearings on the spindle, what in the heck is

wrong with my 13" ????????? When it comes to bearing clearance my lathe will not stay running until it has

at least .014 clearance.

Doesn't make sense at all. Thanks for reading.

One more thing, I'd be happy to share the seller on YouTube that sold me an extra 13" rear bearing if anyone

wants it.


It's now 3:17pm, a few hours later since I posted the above. I powered up the lathe with the current

settings of .008 on the rear and under .002 on the front. It did the usual and got hot. This time I backed

off the expander screws a quarter turn or so and it ran cooler. Would not run on the middle or fast speeds

long at all before you could hear the pitch of the spindle and motor change and take a nose dive. My lathe

has a 3 step pulley spindle. Right now I'm going to remove the spindle and put the bearing and expander in

the headstock. I'm going to measure the diameter of the spindle and see where it corresponds with the

bearing as I tighten the expander. Maybe this will get it back in the ballpark or indicate if I need shims

somewhere else to even it out and position the bearing so I can adjust it to the .001 to .0015
 
Last edited:
Thanks for the info. I understand your concern on line bore, but i can assure you all these 50 to 80 year old machines, that all the line bores are not perfect anymore. Its why i recommend . 001 plus, verse inside of. 001 spindle clearance.

But ultimately I'm sure its not the particular issue here.

First and foremost. It should absolutely spin free by hand. But that is with motor base handle raised, so tension is off flat belt. Also with reversing gears in neutral, center position, so you are not turning gear train.

If it does not spin by hand, loosen each cap separately and tell me when you can spin free by hand. Probably need to play with expander tention in that.

Also, with spindle out. Fill the two oil cups for spindle in head stock. Look at oil holes where spring felts are. How high is the oil level in those two holes ? Now put the two spring felts in. Do they stick up out of hole ?

Other consideration, how fast you turning the spindle ? Top, middle, low speed ? And what rpm rating is electric motor ?
 
Greenlee:
Did you do post 10? You can eliminate a lot of screwing around by doing it.
 
Greenlee:
Did you do post 10? You can eliminate a lot of screwing around by doing it.

To tell you the truth I didn't use any plasticgage mainly because I'm a little confused about the steps. When the cap is pulled off and the expander slid off you see the split bronze bearing with a 3/16" gap. Where do I put the plasticgage and what about the milled slot in the cap for the expander? Please explain the details and steps of how I would do this. Thanks for responding
 
Thanks for the info. I understand your concern on line bore, but i can assure you all these 50 to 80 year old machines, that all the line bores are not perfect anymore. Its why i recommend . 001 plus, verse inside of. 001 spindle clearance.

But ultimately I'm sure its not the particular issue here.

First and foremost. It should absolutely spin free by hand. But that is with motor base handle raised, so tension is off flat belt. Also with reversing gears in neutral, center position, so you are not turning gear train.

If it does not spin by hand, loosen each cap separately and tell me when you can spin free by hand. Probably need to play with expander tention in that.

Also, with spindle out. Fill the two oil cups for spindle in head stock. Look at oil holes where spring felts are. How high is the oil level in those two holes ? Now put the two spring felts in. Do they stick up out of hole ?

Other consideration, how fast you turning the spindle ? Top, middle, low speed ? And what rpm rating is electric motor ?

I'm going out now to work on it now, but to answer some of the questions you have I'll proceed.

When I bought this lathe you could not spin the spindle by hand, you had to have the chuck key in the 4 jaw

to pull it around. Even after I took it apart and set the spindle in the headstock with none of the bearing

caps on it still would not spin by hand. With the addition of the second spindle it spins like a top just

sitting in headstock without the caps. That's a plus right there. The capillary felts do stick up about 3/4"

out of the capillary tubes, I'll have to get back to you on the oil levels with them out when I pull the

spindle out. I have a 3 step pulley spindle on my lathe. The belt is 2-1/8" wide. My motor turns 1725 RPMs

and is a 3 phase 3 HP. My spindle speeds are 270, 497, and 940 RPMs direct drive from motor pulleys to the

headstock pulleys. I'm going to get my pictures uploaded to my PC so I can show you what I found when I

first opened it up. I think something with the bearing cap has changed, I know exactly how to adjust the

bearings for the correct clearance. I think the old machinist might have milled a little off the cap, I can

see a second indication from the machining. What was said in post #5 might come into play with this lathe.

More to come. Thanks
 








 
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