# South Bend 9 lathe Clutch issue



## Talber8 (Dec 30, 2020)

1948 SouthBend 9b Lathe - developed a clutch engagement issue.

After playing with creating knurls in steel, the clutch for the auto feed stopped working.  With the clutch knobbed turned in until tight (3/4 turn) and the selector engaged, the feed is not engaging, and the hand cranks can still be used.

im assuming from the pressure of knurling I may have bent something or flexed a piece out of position.

im assuming the carriage needs to come off but any advice on what I should be looking for?  I’ve never taken the carriage off myself.


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## Jim F (Dec 30, 2020)

Can't help with the clutch issue, I have a C.
This is a good reason to make a clamp type knurling tool,though.


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## Talber8 (Dec 30, 2020)

Jim F said:


> Can't help with the clutch issue, I have a C.
> This is a good reason to make a clamp type knurling tool,though.


 yeah my take-away is don't do this on steel again, lol


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## markba633csi (Dec 30, 2020)

I don't think you broke anything, probably the cone clutch needs adjusting/shimming or is worn.  Pretty sure you have to remove the carriage to fix
-Mark


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## Talber8 (Dec 30, 2020)

Carriage removed, nothing glaring obvious.  When I turn the clutch it spins freely, and those half plates move freely.  But when I screw it clockwise, it should tighten up and and put pressure on the outside right?  They don’t it just free spins


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## lordbeezer (Dec 31, 2020)

Something doesn’t look right with half plate on right. Have you took clutch apart.


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## Talber8 (Jan 2, 2021)

Do I need to remove worm gear to remove the clutch?


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## lordbeezer (Jan 2, 2021)

No. Best I remember unscrew knob on front. Half plates should be loose enough to come out. Check key inside worm for wear while apart


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## lordbeezer (Jan 2, 2021)

You should be able to see what’s not working. Tighten knob. Plates should lock to gear


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## Talber8 (Jan 2, 2021)

I’m not sure what the issue was, but disassemble/reassemble fixed.  I wonder if it was bound at the knob, or where the knob shaft comes out.  I put a good amount t of force on it while it was on the lathe, enough that I knew it was t right at all.  It was dirty but not abysmal.  If it were to happen again, I think I would try with apron still on to losen the star knob a little.

when it happened I was knurling with auto feed, and after that was issue.

I don’t know, but learned a few things! Thanks for the inputs.


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## lordbeezer (Jan 2, 2021)

Did you check the key in worm gear?


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## Talber8 (Jan 2, 2021)

Yeah it operated smoothly...  the key itself looked in good shape, nothing suspect.


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## Glenn Brooks (Feb 25, 2021)

Iam now starting to troubleshoot a similar problem on my earlier, 1925 version of a SB 9. The center knob does not engage either the lateral or horizontal feed.  But, occasionally shows tentative signs of wanting to partially engage- just enuf to bump the lateral cross feed a bit.  And the star knob turns down tight, but doesn’t lock anything.  So the clutch also isn’t functional.  This lathe sat in storage for 65+ years and has no noticeable wear. Iam just getting it running and have no prior experience with it.

A 10 year old thread on another lathe forum suggested the shaft and clutch mechanism often get stuck and do not function when the oil dries up inside the apron.  So Iam thinking simply disassembling, cleaning, and fresh oil in the apron might be in order. 

Wondering if anyone has a photo of the clutch mechanism, or knows what clutch wear is supposed to look like.

Also, Wondering if any SB Guru’s can add any additional recommendations?

Thanks much for any assistance anyone could add.
Glenn P.


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## lordbeezer (Feb 26, 2021)

Post 5 has picture of clutch assy. Cleaning parts would be my first step. Brake Kleen does a good job.


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## Manual Mac (Feb 26, 2021)

Would a 1925 SB9 not be a junior (or heavy) and different than the 1948 in post#5?
Just asking, i could be wrong.


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## mattthemuppet2 (Feb 26, 2021)

my '29 SB9 had a stuck clutch - needed taking apart to clean out the old oil/ gunk and now it locks and unlocks just fine. It's pretty simple, just a male and female cone and some other bits'n'pieces (I did mine a few months ago or I'd be more precise!). The apron is still off so if you need further pointers give me a shout, it'll be easy to take to pieces for pictures.


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## martik777 (Feb 26, 2021)

Also check the wear on your worm gear inside the apron, this was the cause of my 9A was intermittently engaging.


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## Tim9 (Feb 27, 2021)

I’ve had a few of these apart and the half plates all looked just like that. And I had an issue similar to what you described. I’m pretty sure I just cleaned and put back together... added fresh oil, and it worked fine. Do not use way oil in the clutch. It’s too slippery. 
I think that on one of mine where it was slipping.... a piece of swarf was messing up the works.


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## Glenn Brooks (Feb 27, 2021)

Thanks, the pic in post 5 looks just like mine. So afar as I can tell. Don’t have the apron off the lead screw yet- just got it loose and ajar tonight, and cleaned it up a bit, in situ.  Lot of gunk came out just using brake cleaner.  The original owner mostly did wood turning with this. But that was between 1925 and 1938, when he passed away and the machine was palaces into storage by the family - from whom I purchased  it a few years ago. So has been in storage ever since- so far, lots of dried sawdust, dried machine oil and dust clogging up everything I’ve looked at.

I suspect the clutch is probably cracked with this dried residue. Fortunately old oil and saw dust is a superb preservative.

One big question- looks like the only way to get the apron off the lead screw is to run it out the end of the ways, past the tail stock?? Is this correct?

A second smaller question, the tailstoxk locking level is missing. I ran a 5/16” threaded bolt into the insert, but it did not tighten down the tailstock spindle.  So Iam thinking, the spindle locking nut is likely frozen in the tailstock casting.  Can this be pulled out with a bearing puller? Or is there some kind of locking spline or cam inside the housing, that has gotten twisted somehow, preventing movement?? Don’t want to break the casting trying to pull against some physical obstruction inside the trailstock.

In answer to Manual MAC, I do not believe this lathe is a Junior.  I think it is a standard 1925 9” model 61-A.  Don’t have a copy of that specific catalog description in my file, but couple of years ago I found the 61-A catalog on line and it matched the description of the machine. But I do have the original sales receipt, from 1925, and it identifies the lathe as a “9” lathe”.

I am no expert on these early day SB’s, nor their sequence of lathe development, but did see they have had a standard 9” lathe in their line up for nearly all of their early production history, from the early 1920’s maybe even 19 teens through their post war 9” A, B, and C series production.  From what I’ve read, the junior was a separate machine design from their early 9” lathes.

Thanks for your assistance so far!
Glenn


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## lordbeezer (Feb 27, 2021)

Yours might be the workshop model. Later called a,b,c depending on features. Would recommend to replace all wicks. South bend stuck them everywhere. Which is good. Sounds like you have a nice lathe. I have a 37 9” waiting on me to pick up in mountains of Virginia.


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## mattthemuppet2 (Feb 27, 2021)

Glenn Brooks said:


> A second smaller question, the tailstoxk locking level is missing. I ran a 5/16” threaded bolt into the insert, but it did not tighten down the tailstock spindle.  So Iam thinking, the spindle locking nut is likely frozen in the tailstock casting.  Can this be pulled out with a bearing puller? Or is there some kind of locking spline or cam inside the housing, that has gotten twisted somehow, preventing movement?? Don’t want to break the casting trying to pull against some physical obstruction inside the trailstock.



the tailstock barrel/ spindle lock is a 1/2 wedge - the bit under the lever slides down in its bore to clamp against the barrel/ spindle. Take the barrel out, tap it down gently and add oil, then lever it up a bit from inside the tailstock. Keep doing that and it'll free up.

Not sure about the '25 version, but the '29 I have is a New Model Precision 9" lathe according to SB. The workshop moniker didn't arrive until the introduction of the new style narrower bed 9" in A, B and C versions.


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## Glenn Brooks (Feb 27, 2021)

So the Workshop  model is the latter version...  

Edit: so I just searched Steve Wells site and read through the early 1904-1930 SB catalogs he has complied there.  

Looks like SB introduced the 9” series lathes sometime after 1914 and prior to 1923.  These series of lathes are described in their “Junior Lathe” series catalog No. 44 (circa 1914) and No. 79 (1923).   However, in November, 1928, SB introduced a “new model 9” Junior” lathe, (seeCatalog no 23) having fewer features, a new semi steel bed, and a wider apron.  

 Later, in March, 1931, Catalog No.22-c,  SB introduce, for the first time, their newly designed and improved “new model Junior 9” lathe”.  This new  9” “Junior lathe” was built from their existing 9” standard change gear components, but with a wider cone pulley, and without the automatic cross feed function,  friction clutch,  large face plate, center rest, traveler rest, or  quick change gear box. 

Hence, the “Junior” designation appears early on to refer to their introduction of an entirely new, smaller  sized 9” lathe, (Junior to their early smallest 11” lathe).   Then in 1928, they introduced a new 9” Junior Lathe design, as a stripped down, production lathe, having less tooling than  their fully equipped, standard 9” lathe product line. Apparently, SB refined their marketing approach and model designation as they made incremental improvements in lathe design and expanded their product line.

They also changed specific model numbers in successive Catalogs, as they added features, or changed their design. For example, my 1925 9” Lathe is listed in Catalog No. 79, as model 61-A.  “61” referring to a quick Change Gear Box lathe, having “-A”,  a 4’ bed length. 7 years latter, Catalog no. 22-c identifies the modified version of this lathe as model number “82-A”.

Matt,  thanks for the info on the tail stock. Much better than trying to extract with a bearing puller.

Any tips on disassembling the clutch assembly.  The little shaft that holds the star knob seems to be seated pretty tightly into the clutch. I can only unscrew the backing nut a turn or so before everything binds up.  Still need to pull the apron off the shaft to get at the backside.

Glenn


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## mattthemuppet2 (Feb 27, 2021)

just had a quick look and you'll need to take the bracket holding the worm off, then you can either remove the inner part of the clutch (male cone from memory, rides inside the worm gear) with a pin spanner or you can remove the hand wheel and undo the assembly from the handwheel side. I honestly can't remember too much about how it goes together, only that it wasn't that complicated. On mine I think the screw was stuck, so the clutch couldn't be loosened, but it was easy to take apart.


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